数控加工程序中，T指令用于指定（）A、所选用的刀具；B、主轴的旋转速度；C、插补进给

已知：△ABC中，AB=AC，∠A=36°，BD平分∠ABC，则BD=（    ）=（    ），△ABC∽（    ） 。

根据短文内容,从短文后的选项中选出能填入空白处的最佳答案.

     There is an English saying:"1._________." Until recently, few people took the saying

seriously. Now, however, doctors have begun to look into laughter and the effects it has on

the human body. 2. _________.

     Tests were carried out to study the effects of laughter on the body. People watched funny

films while doctors checked their hearts, blood pressure, breathing and muscles. It was

found that laughter has similar effects to physical exercise. 3.__________. If laughter

exercises the body, it must be beneficial(有益的).

Other tests have shown that laughter appears to be able to reduce the effect of pain on the

body. In one experiment doctors produced pain in groups of students who listened to

different radio programs. The group that tolerated(忍耐) the pain for the longest time was

the group which listened to a funny program.4._________.

     5.__________. They have found that even if their patients do not really feel like

laughing, making them smile is enough to produce beneficial effects similar to those caused

by laughter.

A. Laughter can prolong(延长)one's life.

B. As a result of these discoveries, some doctors in the United States now hold laughter clinics in which they help to improve their patients' condition by encouraging them to laugh.

C. The reason why laughter can reduce pain seems to be that it helps to produce a kind of chemicals in the brain which diminish (减少) both stress and pain.

D. It increases blood pressure, the heart beating and breathing; it also works several groups of muscles in the face, the stomach and even the feet.

E. Although laughter helps cure the disease, doctors still can not put this theory into clinic practice.

F. Laughter is the best medicine.

G. They have found that laughter really can improve people's health

肉毒杆菌中毒可见（）

A.注射腾喜龙后症状减轻

B.注射腾喜龙后症状状加重

C.腾喜龙试验无反应

D.腾喜龙试验无意义

E.以上均不是

化学试剂标志等级二级品的瓶签颜色是（）

A.绿色

B.红色

C.蓝色

D.黄色

课程开发工作在职业培训工作中的作用。