第1个回答 2009-10-14
It was mainly caused by two reasons.本回答被提问者采纳
第2个回答 2009-10-14
it mainly caused by two reasons.
第3个回答 2009-10-14
This is caused mainly by two reasons.
第4个回答 2009-10-14
This is mainly caused by two reasons
第5个回答 2009-10-14
this mainly results from the following two reasons