Revision of Unit 3-4
一、单项选择1.What ______ you ______ when your teacher came to the classroom?was,doing    B. were, doing    C. did, do    D. did, doing2. He______ the tree when the cat________ down.was climbing, jumping         B. was climbing, was jumpingC. was climbing, jumped             D. climbed, jumped3. ______ the barber was cutting hair, the alien got out of the UFO. A. While     B. When    C. Where      D. Which4. The woman couldn’t see her son ________. She’s very worried.  A. anywhere ...