633.The thief broke in,trying to open the safe but ________.

A.in vain

B.in no way

C.on no condition

D.on purpose

634.The teacher is writing ______ a piece of chalk on the blackboard while the students are writing ____ ink in exercise books.

A.with,in

B.in,with

C.in,in

D.with,with

633.答案是A;

in vain 徒劳；in no way和on no condition决不；on purpose 故意地。

634.答案是A;

with后接表示工具的名词，而in后接表示材料的名词。