the flu is considered____by viruses which are likely to repr
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
to be caused consider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 the human nose and throat是个定语从句 修饰virus