胸骨角是（）。
A.平对第1肋软骨
B.平对第3肋软骨
C.平对第2肋软骨
D.平对第4肋软骨
E.两侧肋弓之间的夹角
参考答案：C
Whenever we hear of a natural disaster, we feel sympathetic to the people to be affected .
A．to have affected
B．to have effected
C．who have been effected
D．who have been affected
国家安全生产监督管理的权威性首先根源于( )。
A．制度的健全
B．严密的组织
C．坚强的后盾
D．法律的授权
