[单项选择]Only twenty percent of the work（）done yesterday.
A. has
B. was
C. have
D. were

[单项选择]Only twenty percent of the work （　） done yesterday.
A. has
B. was
C. have
D. were

[单项选择]Only ten to twenty percent of cold viruses are transmitted by carders, who, sneezing and coughing, ______ the viruses into the air.
A. spray
B. sprinkle
C. spread
D. sprout

[单项选择]Did you have any difficulty getting this work done
A. 在完成这个工作的过程中你是否遇到了困难
B. 你完成这个工作有什么困难吗
C. 你有困难但还是要让这个工作做成了吗
D. 得到这个工作做起来有困难吗

[单项选择]The ratio of the work done by the machine ______the work done on it is called the efficiency of the machine.
A. against
B. with
C. to
D. for

[填空题]Jerry and Eileen spend twenty percent of their time being writers and for the rest of their time, they have real lives just as ordinary couples do.

[填空题]Only about two percent of Antarctica peeks through the thick sheets of ice that blanket the continent. In the winter, the lowest recorded temperatures (without wind chill) have reached -89℃ (-129°F). The continent averages 2.4 kilometers in height (1.5 miles) above sea level, making it 1.5 kilometers (almost a mile) higher than the global average land height! Each year the South Pole receives less than an inch of water...in the form of snow, of course! This amount of precipitation is similar to that of another desert, the Sahara! Katabatic winds, reaching 300 kilometers per hour (185 miles/hour), blow out of the continental interior and make the Antarctic coastal regions rather breezy.
Antarctica is an important part of Earth’s system. By acting as a global heat sink, it helps control our climate and weather. The stability of the Antarctic ice sheets is of concern to those living in low-lying areas; they contain enough water to raise global sea level almost 70 meters.
Ant

[简答题]Only thirty percent of the local people owned cars at that time. ( periodic sentence)

[单项选择]　　Fishing adds only about one percent to the global economy, but on a regional basis it can contribute extremely to human survival. Marine fisheries contribute more to the world’’s supply of protein than beef, poultry or any other animal source. 　　Fishing typically does not need land ownership, and because it remains, generally, open to all, it is often the employer of last resort in the developing world―an occupation when there are no other choices. Worldwide, about 200 million people rely on fishing for their livelihoods. Within Southeast Asia alone, over five million people fish full-time. In northern Chile forty percent of the population lives off the ocean. In Newfoundland most employment came from fishing or servicing that industry ― until the collapse of the cod fisheries in the early 1990s left tens of thousands of people out of work. 　　Though debates over the conservation of natural resources are often cast as a conflict between jobs and the environment, the restoration of f
A. beef
B. fish
C. pork
D. chicken

[单项选择]Although compact cars make up only 38 percent of the vehicles in traffic, 48 percent of the cars that are followed too closely ("tailgated") are compact. On the other hand, fewer than 27 percent of the cars tailgated are middle-sized, even though middle-sized cars make up 31 percent of the vehicles in traffic.
Which of the following, if true, most contributes to an explanation for the phenomenon described above ？（）
A. The shape of compact cars makes it easy for a tailgater to see far enough ahead around such cars to minimize the chances of a rear-end collision.
B. Middle-sized cars, owned by families with children and pets, are likely to have bumper stickers that are so interesting to read that tailgaters stay behind such cars longer.
C. Compact cars sometimes have superior engines that allow them to pass middle-sized cars on the highway easily.
D. The percentage of cars on the highway that are middlesized has been steadily decreasing over the last decade.
E. Compact cars are often driven by fast drivers.