To be frank, （ ） is a great relief to have the task fulfilled in so short a time.

The engineer tried to （ ） the problem with several drawings.

Since Dick was busy, he rarely had time to go to the cinema; _____.

Our main concern is to _____ the living standard of the people.

Solar energy is a new kind of energy _____ that we can use to replace the traditional energy.

I’m not used to （ ） in that impolite way.

He apologized _____ having to leave so early.

The local government is trying all out to find out who is （ ） the forest fire.

What time would it be convenient _____us to meet again?

Mr. Phillips caught up with the boy in the corridor and （ ） his hand on his shoulder.

Only when （ ） in the afternoon （ ） able to leave.

He （ ） yesterday morning, and would stay for three days.