矿山救护队员在灾区工作1个呼吸器班后，应至少休息（）h，才能重新佩戴氧气呼吸器工作。
A、4
B、8
C、16
D、24
参考答案：B
To our great surprise, we got _____ people to attend the conference as we expected.
A．twice as many
B．twice many
C．twice many as
D．as twice many
已知4个矿泉水空瓶可以换矿泉水一瓶，现有16个矿泉水空瓶，若不交钱，最多可以喝矿泉水 [ ]
A．3瓶
B．4瓶
C．5瓶
D．6瓶
