第1个回答 2009-02-17
some problems are easily arised.
第2个回答 2009-02-17
some common problems本回答被提问者采纳
第3个回答 2009-02-17
Some problems that are easily occured.
第4个回答 2009-02-14
which are vulnerable to the promble of.
第5个回答 2009-02-15
problems which are prompt to happen
problems which are likely to happen