Question

I found_________ hard to learn maths well in such a short time．A.it’s B.this C.that D．its 选啥为

Answer 1

答案应该为A，即 I found (that) it'shard to learn... 本来觉得如果只用it会更通一点~

Answer 2

that在大部分情况中是可加可不加的
只是加了比较顺口
所以是it is
B和C是不能在没有IS的情况下加形容词的

Answer 3

A,我觉得用it was更好。这是一个宾语从句，省略that

Answer 4

it is