请英语语法专家回答
1.It is well konwn ______a person eats causes changes in the body
A.that what B.that C.what D.how
2You will easily know______video recorders are the same
A.what those B.that of those C.that all of Dwhich of those
3.we give him _________help we could
a.what .b.that c.which d.this
怎么没人对啊