Mother was______ doing the cooking when I came in （单选）—4分

After ____________ his work, he came to help me with my English

Any applicant who had worked in this field would receive __________over those who had not.

Not until I began to work ________how much time I had wasted．

When Bill came in, I _____ with my friends.

When Bill came in, I ______ with my friends.

When Bill came in, I______with my friends.

1．_________I came in，Jimmy had already worked out the maths problem．

The message came to the villagers________the enemy had already fled the village.

I’ll never forget the holidays ______ I worked in the factory.

I think _____ knowledge of the Internet is _____ must in our work today.

______ I got home ______ that I had the wrong umbrella.