1.The train is travelling at a (速度)of sixty miles an hour.
答案:speed
2.I have never been to the (沙漠)visited by them.
答案:desert
3.There is some (泥)on his new shoes.
答案:mud
4.Do you know the (乘务员) who is talking with Mr White?
答案:steward
5.There is plenty of (设备) in our lab.
答案:equipment
