关于牙本质过敏症治疗的叙述中错误的是（）。 A．牙本质过敏症可以自愈，不必治疗 B．

某天体在万有引力作用下绕中心天体做匀速圆周运动，当半径变为原来的2倍，下列说法正确的是（　　）

A．根据F_n=m

v2

r

，可知向心力变为原来的

1

2

B．根据F_n=G

Mm

r2

，可知向心力变为原来的

1

4

C．根据F_n=mvω，可知向心力没有发生变化

D．根据F_n=mω²r，可知向心力变为原来的2倍

“起来饥寒交迫的奴隶，起来全世界受苦的人，满腔的热血已经沸腾要为真理而斗争……英特纳雄耐尔就一定要实现”。这首歌诞生于[ ]

A．巴黎公社失败后

B．俄国二月革命后

C．俄国十月革命后

D．中华人民共和国成立后

下列关于虫类药在痹证治疗中的用法哪项不正确（）

A.具有通络止痛、祛风除湿的作用

B.适用于痹证病程较久的抽掣、疼痛、肢体拘挛者

C.包括有地龙、全蝎、蜈蚣、穿山甲、白花蛇、乌梢蛇

D.药量宜大、可久服

E.其中全蝎、蜈蚣二味可研末吞服

New tectmology links the world as never before. Our planet has shrunk. It’s now a "global village" where countries are only seconds away by fax or phone or satellite link. And, of course, our ability to benefit from this high-tech communications equipment is greatly enhanced by foreign language skills. Deeply involved with this new technology is a breed of modem business people who have a growing respect for the economic value of doing business abroad. In modem markets, success overseas often helps support domestic business efforts. Overseas assignments are becoming increasingly important to advancement within executive ranks. The executives stationed in another country no longer need fear being "out of sight and out of mind." He or she can be sure that the overseas effort is central to the company’s plan for success, and that promotions often follow or accompany an assignment abroad. If an employee can succeed in a difficult assignment overseas, superiors will have greater confidence in his or her ability to cope back in the United States where cross-cultural considerations and foreign language issues are becoming more and more prevalent. Thanks to a variety of relatively inexpensive communications devices with business applications, even small businesses in the United States are able to get into international markets. English is still the international language of business. But there is an ever-growing need for people who can speak another language. A second language isn’t generally required to get a job in business, but having language skills gives a candidate the edge when other qualifications appear to be equal. The employee posted abroad who speaks the country’s principal language has an opportunity to fast forward certain negotiations, and can have the cultural insight to know when it is better to move more slowly. The employee at the home office who can communicate well with foreign clients over the telephone or by fax machine is an obvious asset to the firm.

The sentence "Our planet has shrunk" underlined in Paragraph 1 means that ______ .

A．the earth has become physically smaller

B．the more advanced ways of traveling has made the distance between countries shorter

C．the traditional concept of our planet has become out-of-date

D．modem means of communication has made it much easier for people to communicate with each other from different parts of the world

神经元按其作用可分三类，即（）、（）和联系神经元。