1970年美国进行导弹发射试验时，由于操作员对某一个螺母少拧了半圈，导致发射失败。1980年“阿里安”火箭第二次试飞时。由于操作员不慎将一个商标碰落，堵塞了燃烧室喷嘴，导致发射失败。1990年“阿里安”火箭爆炸，是由于工作人员不慎将一块小小的抹布遗留在发动机的小循环系统中。
结合上述案例，你认为事故主要是由()造成的。
A. 螺母质量不过关
B. 对操作人员的选择不严格
C. 管理制度不健全
D. 操作人员没有严格遵守操作规程
查看答案
近年来，内地与台湾的贸易主流形式是()
A. 转口贸易
B. 转运贸易
C. 直接贸易
D. 过境贸易
A．Do research in the library.B．Grade homework sets.C．Teach an introductory economic co
A. Do research in the library.
B. Grade homework sets.
C. Teach an introductory economic course.
D. Make up homework problem.
A．Neighbors should help each other.B．Women should have their own careers.C．Man and wif
A. Neighbors should help each other.
B. Women should have their own careers.
C. Man and wife should share household duties.
D. Parents should take good care of their children.
A．To preserve for a test.B．To tell her if the notes are accurate.C．To help him explain
A. To preserve for a test.
B. To tell her if the notes are accurate.
C. To help him explain the information to his roommate.
D. To help him write a paper.
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