In recent years, there has been a steady attack on salt from the doctors: salt is bad for you--regardless of your health. Politicians also got aboard. "There is a direct relationship," US Congressman Neal Smith said, "between the amount of sodium a person consumes and heart disease, circulatory disorders, stroke and even early death." Frightening, if true! But many doctors and medical researchers are now beginning to feel the salt scare has gone too far. "All these remarks and cry about salt is unnecessary," Dr. Dustan insists. "For most of us it probably does not make much difference how much salt we eat." Dustan's most recent short-term study of 150 people showed that those with normal blood pressure experienced no change at all when placed on an extremely low-salt diet, or later when salt was reintroduced. Of the hypertensive patients, however, half of those on the low-salt diet did experience a drop in blood pressure, which returned to previous level when salt was reintroduced. "An adequate to somewhat excessive salt intake has probably saved many more lives than it has cost in the general population," said Dr. John H Laragh. "So an opinion that the whole population should avoid salt makes no sense." Medical experts agree that everyone should practice reasonable "moderation" in salt consumption. For the average person, a moderate amount might run from four to ten grams a day, or roughly 1/2 to 1/3 teaspoons. One to two grams of salt would come from the natural sodium in food. The rest would be added in processing, preparation or at the table. "Na is not your enemy," says Comek's Dr. Laragh. "Salt is the No.1 natural component of all human tissue, and the idea that you do not need it is wrong. Unless your doctor has proven that you have a salt-related health problem, there is no reason to give it up." What is the experts' advice for average people on salt consumption? A) They should increase salt intake through sodium pills. B) They should avoid salt as often as possible. C) They should consume 1/2 to 1/3 teaspoons of salt a day. D) They needn't care about how much salt they consume.
C
Whenever my dog, Barney, comes into the house after having been for a ride in the car, he runs to the pen we have set up for him by the back door. It's not something we intentionally trained him to do. The habit came simply because my husband tended to put him in his pen whenever they came in. After doing it a few times, Barney just figures that's what you do when you come inside after a car ride. It's the same with your thinking. You get into the habit of thinking a certain way and then you'll rarely question it after that. This is especially true when you were growing up. You developed habits that just made things easier for you. You probably didn't even think about them. That's just the way it was and that's what you did. Just like Barney thinks he has to go into his pen, you do things automatically as well. For example, when you were a kid, you may have been told not to "talk back" and to just keep quiet about things that were bothering you. These are habits that might have worked to keep you safe and out of trouble when you were young. Now that you're grown up, you may be finding that these previous strategies are actually causing you problems. In a relationship, not communicating isn't going to work as your partner can't read your mind. What works when you're a child may not work when you become an adult. When you decide you need to change your thoughts, your brain may at first feel that it's not a safe thing to do. Lots of practice and years of experience says it's not. Also, you don't know to question the thought. It's a truth for you. The trick is to look at your results and see if your thoughts are the cause. Be willing to question your thinking and ask yourself if there are thoughts that are hindering you. As you are now in a different phase of your life, different strategies may be needed. It can be concluded from the passage that _ . A) the author's husband must be good at training dogs B) childhood is the best time for developing good habits C) one can change his/her life by changing his/her thoughts D) you should change all your childhood habits when you grow up
C
*Question*
A green house is a building made of glass which is used for keeping warm when the outside temperature is low. In a similar way there are several gases in the atmosphere (mixture of gases that surround the earth) which trap the heat produced by the sun and prevent it from escaping. These gases are known as "greenhouse gases". And the way in which they trap heat in the atmosphere is called the "greenhouse effect". This is not simply air pollution. Most of the main greenhouse gases exist naturally in small amounts in our atmosphere, and without them the earth would be 30 degrees colder and human life would not exist. In other words, the greenhouse effect is a natural course which is to some degree helpful to us. The problem is that in the last century and a half, we have been putting too many of these gases into the earth's atmosphere by burning large quantities of coal and oil and by cutting down forest. The rapid increase in greenhouse gases is making the world warmer. The world's temperature has already gone up by half a degree this century, and the sea level has risen by 10 centimetres. If the amount of carbon dioxide in the atmosphere doubles, there will probably be a rise in the earth's temperature of between I and 4degC;. This may seem a small increase, but it would be enough to cause major changes in geography and agriculture. Large areas of the world would be flooded, and some areas would become dry and unable to produce crops. It is important, too, to consider that there may be a delay of about 30 years in the greenhouse effect. This means that we are probably experiencing only now the effect of the gases put into the atmosphere before the 1960s. Since then, our use of these gases has greatly increased. According to the passage, we can know "greenhouse effect" means _ . A) the way in which gases are used for keeping plants warm B) a natural course that is to a certain degree useful to us C) the way "greenhouse gases" trap heat on the earth D) the whole course in which greenhouse gases prevent heat
**Answer**
B