21. _______ successful docking of Shenzhou VIII with Tiangong-I means that China has managed to take ________ first important step to establish its own space station.
A. /; / B. A; a C. The, a D. The; the
22. Mr. Brown knows little Japanese，so he can't understand the ________ on the bottle of the pills.
A. explanations B. instructions
C. suggestions D. introductions
