请帮我做几道英语选择题,并简要说明下原因

请帮我做几道英语选择题,并简要说明下原因
1.She asked me if i knew( )
A.whose pen it was B.Whose pen was it
2.You must remember( ).
A.what your mother said B.What did your mother say C.your mother said what D.what has your mother said
3.Did you know(
A.what your mother said B.what did your mother say C.your mother said what D.what has your mother said
4.Could you tell me(
A.when will they leave Beijing B.when would they leave Beijing C.when they will leave Beijing D.when did they leave Beijing
5.I don’t know( ).Can you tell me,please?
A.how the two players are old B.how old are the two players C.the two players are how oldD.how old the two players are
6.I was told( )Bill Gates was thirteen he began to play with computers.
A.that how B.that when C.when that D.how that
7.He thinks( ) very important to learn English well.
A.this B.that C.it D.its