人体对缺氧最敏感的组织是（）
A.心脏
B.肝脏
C.大脑皮层
D.肺脏
E.肾脏
参考答案：C
横线上最大能填几？
______×24＜100 46×______＜217．
Be careful not to ______ your bike with so many heavy bags.
A．turn off
B．set off
C．take off
D．fall off
