the flu is considered____by viruses which are likely to reproduce in the cells inside the human nose and throat
问题描述：
the flu is considered____by viruses which are likely to reproduce in the cells inside the human nose and throat
causing
being caused
to be caused
to have caused
答
to be causedconsider有两个用法.表示考虑的时候是consider doing表示认为的时候是consider sth to be,所以这里是sth is considered to be caused by virus下面的which are likely to reproduce in the cells inside...