If sufficient rain falls the next year to form another lake, the eggs hatch, and once again the shrimps pass rapidly through their cycle of growth, adulthood, egg-laying, and death. Some years there is insufficient rain to form a lake: in this case, the eggs will remain dormant for another year, or even longer if necessary. Very, very occasionally, perhaps twice in a hundred years, sufficient rain falls to form a deep lake that lasts a month or more. In this case, the species passes through two cycles of growth, egg-laying, and death. Thus, on such occasions, the species multiplies considerably, which further ensures its survival.

　　21. Which of the following is the MOST distinctive feature of Mojave shrimps?

　　A) Their lives are brief.

　　B) They feed on plant and animal organisms.

　　C) Their eggs can survive years of drought.

　　D) They lay their eggs in the mud.

　　22. By saying “for the shrimps it is a race against time” (Para. 3, Line 2) the author means .

　　A) they have to swim fast to avoid danger in the rapidly evaporating lake

　　B) they have to swim fast to catch the animal organisms on which they survive

　　C) they have to multiply as many as possible within thirteen days

　　D) they have to complete their life cycle within a short span of time permitted by the environment

　　23. The passage mainly deals with .

　　A) the life span of the Mojave shrimps C) the importance of water to life

　　B) the survival of desert shrimps D) life in the Mojave Desert

　　24. The word “dormant” (Para. 4, Line 3) most probably means .

　　A) inactive B) strong C) alert D) soft

　　25. It may be inferred from the passage that .

　　A) appearance and size are most important for life to survive in the desert

　　B) a species must be able to multiply quickly in order to survive

　　C) for some species one life cycle in a year is enough to survive the desert drought

　　D) some species develop a unique life pattern to survive in extremely harsh conditions

　　Questions 26 to 30 are based on the following passage:

　　Opportunities for rewarding work become fewer for both men and women as they grow older. After age 40, job hunting becomes even more difficult. Many workers stay at jobs they are too old for rather than face possible rejection. Our youth-oriented, throw-away culture sees little value in older people. In writer Lilian Hellman's words, they have “the wisdom that comes with age that we can't make use of.”

　　Unemployment and economic need for work is higher among older women, especially minorities, than among younger white women. A national council reports these findings: Though unemployed longer when seeking work, older women job-hunt harder, hold a job longer with less absenteeism (缺勤), perform as well or better, are more reliable, and are more willing to learn than men or younger women. Yet many older women earn poor pay and face a future of poverty in their retirement years. When “sexism meets ageism, poverty is no longer on the doorstep — it moves in,” according to Tish Sommers, director of a special study on older women for the National Organization for Women.

　　Yet a 1981 report on the White House Conference on Aging shows that as a group, older Americans are the “wealthiest, best fed, best housed, healthiest, most self-reliant older population in our history.” This statement is small comfort to those living below the poverty line, but it does explode some of the old traditional beliefs and fears. Opportunities for moving in and up in a large company may shrink but many older people begin successful small businesses, volunteer in satisfying activities, and stay active for many years. They have few role models because in previous generations the life span was much shorter and expectations of life were fewer. They are ploughing new ground.��

　　Employers are beginning to recognize that the mature person can bring a great deal of stability and responsibility to a position. One doesn't lose ability and experience on the eve of one's 65th or 70th birthday any more than one grows up instantly at age 21.

　　26. After the age of 40, .

　　A) most workers are tired of their present jobs

　　B) many workers tend to stick to their present jobs

　　C) people find their jobs more rewarding than before

　　D) people still wish to hunt for more suitable jobs