单选题Most comets have two kinds of tails, one made up of dust, ________made up of electrically charged particles called plasma.

单选题Donkeys and camels are still widely used in some parts of the world as beasts of______.

单选题______ famous queens in the history of England: Elizabeth I and Victoria.

单选题It has been estimated that only 21 percent of______world's land surface can be cultivated and that only 7.6 percent is actually under______cultivation. A．/.../ B．the...the C．/...the D．the.../

单选题Everything，including the clothes in the closets，______stolen from the apartment.

单选题{{U}}In spite of{{/U}} relatively costly, the diesel engine is highly efficient and needs servicing infrequently.

单选题In his speech at the conference, the Chairman solemnly stated that the responsibility to our lives and the kind of world {{U}}in that{{/U}} we live is ours and ours alone.

单选题The patient strongly objected to______like this.

单选题______ their final medical check, the astronauts boarded their spacecraft.

单选题At the end of the valley we turned right, and made for the summit. A. headed for B. went for C. looked for D. searched for

单选题Motivation is the driving force within individuals that impels them to action. A. impedes B. interferes C. holds D. pushes

单选题The most {{U}}striking{{/U}} technological success in the 20th century is probably the computer revolution.

单选题The hard, out surface of the tooth is called enamel. A. outside B. appearance C. outer D. hiding

单选题Teachers and nurses who deal with children are obliged to report cases of suspected child abuse to authorities.

单选题The shortage of rainfall this summer in the region is sure to cause ______ of vegetables for the food market. A. scarcity B. variety C. rarity D. validity

单选题Modem man is careless when disposing ______ his garbage. A. of B. to C. at D. about

单选题Pam loves children but she doesn't like them when they're noisy. It gets on her ______.

单选题When Mary discovered how treacherous the streets could be, she demanded that her boys stay close to her in the church gym and youth center, and the boys were {{U}}as good as gold{{/U}}, listening to every word she says.

单选题In our own galaxy, the Milky Way, there are perhaps 200 billion stars, a small part of them probably have planets on which life is feasible.

单选题Comparisons were drawn between the development of television in the 20th century and the diffusion of printing in the 15th and 16th centuries. Yet much had happened (91) . As was discussed before, it was not (92) the 19th century that the newspaper became the dominant pree-leetronie (93) , following in the wake of the pamphlet and the book and in the (94) of the periodical. It was during the same time that the communications revolution (95) up, beginning with transport, the railway, and leading (96) through the telegraph, the telephone, radio, and motion pictures (97) the 20th-eentury world of the motor ear and the airplane. Not everyone sees that process in (98) . It is important to do so. It is generally recognized, (99) , that the introduction of the computer in the early 20th century, (100) by the invention of the integrated circuit during the 1960s, radically changed the process, (101) its impact on the media was not immediately (102) . As time went by, computers became smaller and more powerful, and they became "personal" too, as well as (103) , with display becoming sharper and storage (104) increasing. They were thought of, like people, (105) generations, with the distance between generations much (106) It was within the computer age that the term" information society" began to be widely used to describe the (107) within which we now live. The communications revolution has (108) both work and leisure and how we think and feel both about place and time, but there have been (109) views about its economic, political, social and cultural implications. "Benefits" have been weighed (110) "harmful" outcomes. And generalizations have proved difficult.