Most people make such mistakes （ ） in their whole life.

_____, the professor is still trying to learn a new language.

Yon don’t have the right to blame me _____ being late， for I was busy typing your business invitations.

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

（ ） when she started complaining.

Neither his family nor he （ ） anything about it.

The audience stood and （ ） at the end of the performance.

These tickets for the performance are （ ） until the end of the month．

Plastics is a kind of （ ） which is widely used in industry.

The defense computers calculate way to （ ） the enemy missiles.

When I was a child, I used （ ） to the river and bathe in the evening.

Without your instruction, I （ ） such great progress.