The classroom is big enough________, but we'll have to move if we have more students.
21. --- Why don’t you like your job ? --- It’s always being ___by my director .
20. The rest of his life was devoted ___ pollution ___more happily .
19. --- Could you tell me how the sea sand comes about ? --- Sea waves dash against the rock. In this way , the sea sand ___ .
18. A new ___ bus service to Tianjin Airport started to operate two months ago .
17. Greatly moved by what he did , ____ .