He thought( )a little difficult to work out this maths problemthere /it/this/that选词填空
问题描述：
He thought( )a little difficult to work out this maths problem
there /it/this/that
选词填空
答
it
he find/think/suppose it adj.to do sth.
答
that, 只能填that,因为that不能当任何成分。
如果选其他任何一个，多时充当主语的，都必须在后面跟一个be动词！
如果没有be动词，主语也不能要，这叫主谓同省！
主谓要么同时省略，要么都不能省略，下面是都不省略的例子！
he thought that it is a little difficult to work out this maths problem.
答
it
it 在这里做形式宾语
答
it