建筑模板支架施工中，以（）结构最为广泛。
A、扣件式钢管
B、碗扣式钢管
C、门式钢管
D、木式
参考答案：A
The 29th Olympics Games _____ in Beijing in 2008. [ ]
A. is held
B. was held
C. will be held
D. has been held
甲状腺功能亢进的临床表现，不正确的是（）.
A.高代谢综合征
B.紧张焦虑，手和眼睑震颤
C.心动过速，心律失常
D.便秘，排便次数减少
E.可出现周期性瘫痪和肌无力
