问题

What did your mother say, Tom -She asked me why _ __.
A:;my;sister;was crying;
B:;my;sister;is;crying;
C:;is;my;sister;crying;
D:;was;my;sister;crying;
B:;my;sister;is;crying;
C:;is;my;sister;crying;
D:;was;my;sister;crying;
正确答案是: