This missile is designed so that once _____ nothing can be done to retrieve it.

He resented _____ to wait. He expected the minister _____ him at once.

He noticed the helicopter hovering over the field. Then to his astonishment, he saw a rope ladder _____ out and three men climbing down it.

The country’s chief exports are coal, cars and cotton goods, cars _____ the most important of these.

_____ regular training in nursing, she could hardly cope with the work at first.

Arriving at the bus stop, _____ waiting there.

I never regretted _____ his offer, for it was not where my interest lay.

I don’t like _____ bills but when I do get them I like _____ them promptly.

The compositions contained so few errors that the teacher got the students _____ one another ’s papers.

It’s high time we _____ cutting down the rainforests.