【正文】
he right words to plete it. Answers: (1) heard (2) been doing (3) been researching (4) been doing (5) started (6) done (7) read (8) found (9) started (10) been doing (11) been making 2. Try to answer the following questions according to the ic strip. (1) Where do you think the boy has been waiting? (He has been waiting at an underground station.) (2) What have the aliens been traveling in? What does it look like? (They have been traveling in an UFO. It looks like a saucer.) (3) Who else have the aliens talked to? (They probably have talked to animals or plants on the earth as