单选题Since 1939, numerous scientific studies __ to determine whether smoking is a health hazard.
单选题Many live in Hawaii, more than __ of whose people boast on Asian or
Polynesian heritage.
单选题The modem __ long pencil can draw a line 35 miles in length.
单选题The assumption _____ human cloning rests is that all genetic cells contain exact copies of the original set o9f genetic instructions.
单选题The driller is unlucky when
单选题The Buick driver, a former convict, had been ______ from the Oklahoma county jail only a week before.
单选题They found that the positive thinkers sold 37 percent more insurance than did the_______ thinkers.
单选题We've bought a new house. We'll move in soon and we need to buy __ furniture.
单选题Although baleen whale may weigh ______ twenty elephants, it feeds on sea plants and animals.
单选题Speakers and writers of the Germanic languages _______for a great deal of the world's output in everything from economics to literature to military to science and technology.
单选题Ecology, __ the relationships between organisms and their environments, is also important in petroleum geology.
单选题The cost of self-education has fallen with the multitude of sources of knowledge and information _______ on CD-ROMs and the Internet.
单选题The Chinese nation has __ significantly to the progress of human civilization.
单选题It’s difficult to divine what constitutes an ______ tip in any country.
单选题Some times aftershocks follow an earthquake for as long as
单选题He preferred not to__ with that group.
单选题This is an old clock that is not only very beautiful but __
单选题What is true about the GREAT program?
单选题None of the waiters were____ when Mr. Smith wanted to order dishes in the restaurant.
单选题The football player is hoping to ______ to another club.