问题补充:
—Tomorrow my birthday. I’d like you and Jane to come.
—I’m not sure if she free.
A. will be; is
B. is going to; is
C. is; is
D. is; will be
答案:
A. will be; is
B. is going to; is
C. is; is
D. is; will be
解析:第一空是表示“不以人的意志为转移的客观事实”,用一般现在时;第二空是表示“将来的动作”,用一般将来时。