The twin brothers stand under the tree, ______ and say nothing.
| A．puzzled | B．puzzling |
| C．being puzzling | D．being puzzled |
_______is often the case,he succeeded in this examination again.
| A．What | B．So | C．Which | D．As |
_ _______broken,the glass can not hold water.
| A．Once | B．After | C．On | D．Though |
_I had just started back for the house to change my clothes_______I heard voices.
| A．as | B．when | C．after | D．while |
_By success I don’t mean_______usually thought of when that word is used.
| A．what is | B．what has | C．that is | D．that has |
_For six or seven months in the year,no work can be done, _______the rainy season makes it impossible.
| A．while | B．until | C．before | D．when |