_______ his research, man can set foot on the moon now.
the bad weather, most of the crops are rotted away.
In ancient times, people rarely travelled long distances and most farmers only travelled the local market.
We looked forward to _______ at eight in the morning, but he didn’t turn _______ until 9 o’clock..
The teacher apologized late.
_____ in a heavy rain, the teacher fell ill and couldn’t but ______ for a leave.