过剩空气系数（）空气供给量与（）空气需要量之比。
参考答案：实际、理论
手机+笔记本电脑的资费：按（）资费标准收费。
A.CMNET；
B.CMWAP；
C.CSD；
D.以上都不对。
—Can you describe a distinctive characteristic of this animal?
—Its neck can be extended ________ of its body.
A．more than twice the length
B．twice more than the length
C．more than the length twice
D．more twice than the length
