Every year gray whales swim a 10,000 miles round-trip, from the cold waters near Alaska, down the coast of North America to the warm waters near Mexico, and back again. It is one of the longest migrations of any mammal. All day, all summer long, in the cold waters near Alaska, gray whales eat and eat. Instead of teeth, gray whales have baleen, they are used to getting food from ocean water. They get big mouthfuls of muck from the ocean floor, then push that muck right back out through their baleen. The mucky water flows through, but tiny animals get trapped in the baleen and _ . When the water starts to freeze, the whales begin their long trip south. They swim night and day, without stopping to eat or rest. During the long journey, migrating whales may push their heads out of the water to see where they are. Two months later, the whales reach Mexico. Babies are born here in warm, shallow waters called lagoons. Ocean lagoons have no food for the adults, but the babies are safer here than in the open seas. All winter the babies grow big and strong. In spring first the dads and teenagers leave the lagoons, then the moms with babies. Migrating gray whales swim close to shore, especially moms with babies. The ice is melting up north, and it's time for the hungry whales to make the long journey back to their summer feeding grounds. During their long journey to Mexico, gray whales _ . A) always swim under the ocean B) find food to supply their energy C) face the colder and colder water D) travel to the lagoons without a break
A
From New Delhi to Beijing,commuters spend a lot of time stuck in traffic.In the United States,Los Angeles(L.A.)and San Francisco tie for second place for having the worst traffic problems.Washington,D.C.is in first place with the worst traffic,according to the Texas A&M Transportation Institute. In L.A..drivers spend sixty-one hours every year stuck in traffic.These drivers know all too well how bad the traffic can be.Professor Cyrus Shahabi also knows about traffic jams.He said,"It's a prison of cars.There are too many cars,you can't move around a lot.I live more than 65 kilometers from my office at the University of Southern California.in L.A..I'm always late even with the help of a navigation system.I thought it would be appropriate to do something to solve it." Therefore,he and PhD student Ugur Demiryurek decided to develop an app for that.The ClearPath app claims to do what other navigation systems cannot.Professor Shahabi says his program uses historical data to predict traffic conditions even before the driver leaves the house. ClearPath uses two and a half years worth of traffic data from 9,000 sensors on the roads of L.A..It also collects information on accidents. Professor Shahabi says his system does more than just respond to current traffic conditions.With ClearPath,he says,a driver can enter what time he wants to leave on a specific time and date,and ClearPath will give the fastest route.It looks at the entire road network,including surface streets as well as highways,before the driver hits the road. Ugur Demiryurek says they will launch the free ClearPath app for roads in L.A.in two months.In a year,he and Professor Shahabi hope to have ClearPath available nationwide and overseas once they can collect traffic data from other cities. "I thought always that L.A.had the worst traffic,but now I know that Shanghai,Beijing,Seoul,Tokyo,believe it or not,Singapore,Hong Kong definitely are examples that can immediately use this." The ClearPath app can mainly be used to _ . A) predict traffic conditions B) kill the boring time C) avoid the traffic accidents D) collect the current news
C
*Question*
When you choose a freezer, remember it's probably going to be with you for a long time. So it's important to know which freezer is right for your needs. First, decide if you want an upright or chest model. Uprights are more convenient. Their storage space is more accessible and they take up less floor area. However, chest models are more energy-efficient because less cold air escapes when they are open. If you are buying an upright, you'll have to choose between frostless or manual defrost . Chest freezers are always manual. Frostless freezers automatically defrost at present intervals and remove the water. Manual models must be defrosted by hand every few months or whenever frost pile up to about a quarter of an inch. To help your freezer reach a ripe old age, try to find a spot that's cool, dry, and away fromdrafts . Drafts and heat will raise the freezer's cabinet temperature, which makes it work harder to keep cool. That means wasted energy. That means wasted energy and a shortened life. Dry air is important because highhumidity can cause the freezer to rust outside and frost up inside. With proper care, a freezer can serve you for 15 years or more. Regular cleaning and simple maintenance will help it maintain a zero-degree temperature and keep it smelling fresh and looking almost new. Frostless models requires less care than manual defrost freezers. The inside of a frostless unit should be washed periodically with warm water and baking soda or a mild soap, rinse, and dried. Good habits go a long way toward a freezer that runs efficiently. To get the most from your freezer, check regularly to make sure it's providing a true zero-degree temperature. Keep the freezer at least three-quarters full. The emptier it get, the more energy is wasted. If more than three pounds of food per cubic foot of storage space is added every 24 hours, the resulting high or low temperature can damage the food. In order to get the best results, you should _ . A) use cool water to wash the inside of frostless models B) keep the freezer at least 75% full C) add three pounds of food every 24 hours D) put your freezer in a garage with a strong floor
**Answer**
B