单项选择题
Which one of the following is not relevant to the others?（）
A.airport B.airfield C.airline D.air-conditioned
单项选择题 It must be difficult for her to cope（）three small children and a job.
单项选择题 The club（）children between the ages of 4 and 12.
单项选择题 It is（）that we could only stay there for three weeks.
