You know that balloons must be kept away from sharp objects. They also needed to be kept away from flames. A fire can weaken the rubber and cause it to break. However, in this experiment you will find out how you can hold a balloon directly in a flame without breaking the balloon. Materials needed: * two round balloons not inflated * several matches * water Inflate one of the balloons and tie it. Place 1/4 cup of water in the other balloon, and then inflate it and tie it. Light a match and hold it under the first balloon. Allow the flame to touch the balloon. What happens? The balloon breaks, perhaps even before the flame touches it. Light another match. Hold it directly under the water in the second balloon. Allow the flame to touch the balloon. What happens to this balloon? It doesn't break. Why does the balloon with no water break in the flame? The flame heats the rubber of both balloons. The rubber of the balloon without water becomes so hot that it becomes too weak to _ the pressure of the air inside the balloon. However, when the balloon with water in it is placed in the flame, the water takes in most of the heat from the flame. Then, the rubber of the balloon doesn't become very hot, it doesn't weaken, and the balloon doesn't break. Water is a particularly good absorber of heat. It takes a lot of heat to change the temperature of water. On the other hand, when water cools, it gives off a great deal of heat. That's why areas near oceans or other large bodies of water don't get as cold in winter as areas at the same latitude further inland. When the flame reaches the balloon with water inside, _ A) the rubber of it doesn't become hot at all B) the water in it begins to boil C) the balloon breaks D) the heat is mostly taken in by the water
D
(Question)
COLUMBUS, Ohio--The heart operation taking place in the pale-green operating room at the Ohio State University Medical Center was unusual. The patient, a 62-year-old man, was made to sleep, tied with blue drapes and lying face up on a narrow table. But no one was touching him. Instead, the operation was being performed by a robot, whose three metal arms went through pencil-sized holes in the man's chest. At the ends of the robot's arms were tiny metal fingers, with turning wrists, which held a tiny instrument, a light and a camera. The robot's arms and fingers were controlled by Dr. Randall K. Wolf, sitting at a computer in a corner of the operating room about 20 feet away. This sort of operation, heart surgeons say, is the start of what may be the biggest change in their profession since heart bypass surgery began nearly 30 years ago. "The reason we make cuts is that we have big hands," said Dr. Wolf, the director of the surgery at Ohio State. The robot's _ fingers, no longer than a nail on the small finger, at the end of the long sticks could work better. Eventually, surgeons believe, most heart surgery will be done by robots whose arms are put in through pencil-sized holes punched in patients' chests. Instead of directly staring into a patient's body, surgeons will view magnified images of the operation on computer screens. In theory, the doctor would not have to be in the same room, or even the same country, as the patient. The main idea of this passage is that heart surgery by robots _ . A) is quicker than surgery done by doctors B) may replace surgery done by doctors C) is a new and risky procedure D) was developed at Ohio State University
(Answer)
B
Ques: Encouraging early reading skills can build a path to a lifelong love of reading and can help your child get a head start in school. While reading to your child is still the most important thing you can do to build reading skills, there are many techniques that can help. Make reading fun. Play games with your child as you read. Many traditional children's games can be adapted to encourage reading skills. While reading or during play, tell your child, "I spy with my little eye, something that begins with the letter "b". Help the child find something on the page or in the room that begins with that letter. For example, "I see a barn." This can also be used to teach beginning letter sounds.Ispy with my little eye something that begins with the sound "s". Help the child find a word that begins with the "s" sound. In this variation on the popular game, instruct the child that, "Simon says, point to something that starts with the letter "n". The child can then find an object in the room or a body part, such as the nose, that starts with the letter presented. This can also be used to teach beginning sounds. Make a game out of rhyming words by making up silly words to rhyme with the child's name or favorite toys. This sets the stage for rhyming real words by showing the child the similarities of sounds. As the child masters making up the words, begin rhyming real words to one another. Tips to raise a successful reader: Put books in places where the child plays. If books are easily _ , children are more likely to pick them up. Let children "read to you" by looking at pictures. Making up stories to go along with illustrations helps children discover how words relate to pictures. Take books along on trips or even short visits to the doctor's office or grocery store. Have children help you shop. Reading grocery lists and looking for specific items helps build vocabulary. What can we conclude from the text? A) The most important thing is to make reading funny. B) Children have a preference for stories with pictures. C) Rhyming games should begin only with real words. D) Children tend to read more if books are at hand.
Ans: D
The most important holiday in spring, especially for Christians , is Easter. This Christian holiday is not on the same date every year, but it's always on a Sunday. It can be any Sunday between March 22 and April 25. Many people celebrate Easter by buying new clothes. Children celebrate by hunting for color1ed eggs that their parents have hidden around the house. People also give Easter baskets filled with candy and other goodies to one another to celebrate the day. But the holiday is more than new clothes and good things to eat. On Easter, many people go to church to celebrate Jesus' resurrection from the dead. Most people color1 them. Some people hide them. Others just eat them. But no matter what one does with Easter eggs, they are an important Easter tradition throughout the Western world. People from many different cultures celebrate Easter. In both America and Belgium, children look for Easter eggs hidden on lawns and in bushes. In America, children believe the eggs are hidden by the Easter bunny . But in Belgium, the hidden eggs are supposed to have fallen from church bells. In Bulgaria, red Easter eggs are lucky in churches; Bulgarian families also hit these Easter eggs together to see whose is the strongest. The winner looks forward to good fortune that year. Still dozens of other Easter traditions exist. In parts of Austria, for example, children sing from door to door and are rewarded with color1ful eggs. To celebrate Easter, people _ . A) go shopping, hide color1ed eggs and children hunt for them B) give Easter baskets filled candy and goodies to one another C) buy new clothes, hide color1ed eggs and children look for them around the house D) both B and C
D