放完电后的铅蓄电池必须在（）。
A.12h内充足电
B.24h内充足电
C.36h内充足电
参考答案：B
30. —I _________ his telephone number.
—I have his number, but I _________ to bring my phone book.”
A．forget, forget
B．forgot, forgot
C．forgot, forget
D．forget, forgot
什么叫钻进？
