第一节 单项填空(共15题；每小题1分，满分15分)
21.He spent too much time talking on phone while we were all busy at work..
A. the; / B. a; / C. / ; / D. the; the
22.—How can I use this washing machine?
—Well, just refer to the .
A. explanations B. expressions C. introductions D. directions
