课尾达标微测及时巩固 检测知不足用所给词的适当形式填空 1．where have you been, david? we ________ (look) for you everywhere. 答案 have been looking 2．he ________ (collect) all kinds of stamps since he was ten years old. 答案 has been collecting 3．he ________ (listen) to english programmes since he came to
