为了使进入工件的波型转换为横波，除选择适当的入射角外，楔块的_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题填空题

为了使进入工件的波型转换为横波，除选择适当的入射角外，楔块的纵波声速还要比工件的横波声速（）。

答案

参考答案：小

单项选择题 A1型题

经前或经期吐血、衄血，量少，色鲜红，头晕耳鸣，手足心热，咽干口渴，月经量少，或无月经，舌红或绛，苔花剥或无苔，脉细数。治疗方剂（）

A.百合固金汤

B.麦门冬汤

C.顺经汤

D.丹栀逍遥散

E.逍遥散

填空题

Part 4

Questions 26-45

·Read the following passage and decide which answer best fits each space.
·For questions 26-45, mark one letter A, B, C or D on the Answer Sheet.
Participation (26) high school sports is not a constitutional right. (27) , it is a privilege, paid for by taxpayers, open to students who promise to (28) certain conduct requirements on and off the field. One of these promises is to (29) from using drugs. Drug use is a serious problem among high school students. Studies show that as many as 500, 000 high school students use muscle-pumping, life-destroying substances such as steroids. Many more use illegal drugs, (30) cause discipline problems and (31) the stage for lifelong (32) .
Drug testing works to (33) and identify use. That is why drug testing is required to compete in the Olympics, the National Collegiate Athletic Association and the National Football League. (34) drug testing was instituted by these organizations, use of performance- (35) drugs has been greatly reduced. We should want (36) in schools.
Indeed, many athletes (37) testing programs, and no wonder. Without testing, athletes have to choose between drug use and a competitive disadvantage (38) the field.
Those who challenge the need for drug testing may be forgetting (39) it is like be an adolescent. Peer pressure is enormous, and one of the few effective counter-weights is the fear of being caught. More importantly, once drug use is (40) , a school can (41) to the student before he or she gets addicted or arrested.
For 25 years, public schools (42) by federal judges and civil libertarians, with results everyone can see. It is time (43) decisions on how to run public schools locally (44) officials. There is nothing unconstitutional about asking those who gain the advantages of school-sponsored athletics to contribute to the safety of other players, the integrity of the game and their own well-being. The Supreme Court should leave these programs (45) .

A．Since

B．After

C．When

D．While