20.A.fond　　　　　 B. proud　　　　　 C. sure　　　　　　 D. kind

　　　　　　　　　　　　　　　　　 (10)

　　 In about 250 BC, the Greek scientist Archimedes was asked by King Hieron to find out if his crown was 　1　 　gold. Archimedes thought and thought about the problem. Suddenly the 　2　 　came to him when he was having a 　3　 .

　　 As he got into the bathtub, Archimedes 　4　 　that if he immersed(浸入)the King's crown in a vessel 　5　 　to the brim(边缘) with water, it would cause some water to 　6　 . If he then immersed a piece of pure gold of the same 　7　 as this crown, the same amount of water would overflow if the crown was pure gold. 　8　 , Archimedes found that the crown was not pure gold.

　　 He is believed to have rushed naked(赤裸) from his bathtub into the 　9　 　shouting, "Eureka!", which means, "I've 　10　 　it!"

　　 Archimedes made many important scientific 　11　 , including pulleys, and he first explained why things float.

　　 A one-word code was 　12　 　from Kissinger(基辛格) to Nixon(尼克松), “Eureka”, meaning that the trip had been 　13　 . After returning from Beijing, Kissinger and his assistant wrote a 　14　 　to Nixon, “We have laid the 　15　 work for you and Mao to turn a page in 　16　 ." On July 15 Nixon informed stunned television viewers of Kissinger's 　17　 　trip and his own 　18　 　to visit China some time before May 1972. In October 1971, Kissinger returned to　 19　 , with a team of “advance men”, to 　20　 　for Nixon's own visit.

19.A.take　　　　　 B. create　　　　　 　C. give　　　　　　 D. forgive

17.A.school　　　　 B. friends　　　　 　C. students　　　　 　D. children

tributed　 　B. delivered　　 　　C. sold　　　　　　 D. lent

16.A.troubling　　 　B. disturbing　　 　　C. reminding　　　 D. thanking

15.A.wherever　　　 B. however　　　　 C. whenever　　　　 D. whatever

14.A.showing　　　 B. moving　　　　　 C. handing　　　　 D. driving

13.A.much　　　　 B. them　　　　　　 C. little　　　　　 　D. qualities

12.A.worried　　　 B. stopped　　　 　　C. laughed　　　　 　D. examined

11.A.join　　 　　　B. fill　　　　 　　C. keep　　　　　　 　D. have

10.A.off　　　　　 B. out　　　　　　 C. down　　　　　　 D. up and down