第一部分: 单项选择 (满分30分)
1. He had been so absorbed ____ watching the car passing by that he didn’t notice his friends ______.
A. to; coming B. in; to come C. on; coming D. in; coming
2. Each time ____ he came to Xi’an, he would drop in to see me.
A. which B. when C. / D. during
