任何一个数都有倒数．______．
因为0没有倒数，所以任何一个数都有倒数是错误的．
故答案为：错误．
Laura was away in Paris for over a week. When she got home, there was a pile of mail _______ for her.
A．waited
B．to wait
C．waiting
D．was waiting
由于能量利用障碍而发生心衰最常见的原因（）。
A.甲状腺机能减退
B.高血压
C.肺动脉高压
D.贫血
E.高钾血症
