式输送机长度超过（）时，各重要工作地点，必须设置中间“紧急停机”按钮或拉线开关。A、

某小学有学生1200人，每个学生一天上5节课，每个老师一天教4节课，每个班有1名教师和30名学生，那么这所学校共有教师______名．

Entering the reading room, ______.

A．Mike and Tom were found seated quietly, doing their homework

B．Mike and Tom were found seating quietly, doing their homework

C．he found Mike and Tom seating quietly, doing their homework

D．he found Mike and Tom seated quietly, doing their homework

柏子仁除润肠通便外，又能（）

A.补气

B.敛汗

C.养心安神

D.清热解毒

E.利水消肿

中央上DU的全温显示数据来自（）

A、ADIRU1

B、ADIRU2

C、正常来自ADIRU1，当ADIRU1故障后来自ADIRU2

D、全温探头

多模光纤获得稳态模分布的光学装置有三种功能器件（）、（）、（）。