Is that your best friend Kitty?— No it be her. She flew to Singapore yesterday.A. mustB.

问题补充：

Is that your best friend Kitty?

— No, it be her. She flew to Singapore yesterday.

A. must

B. can

C. Mustn’t

D. Can’t

答案：

A. must

B. can

C. Mustn’t

(答案→)D. Can’t

解析：根据She flew to Singapore yesterday “她乘飞机去新加坡了。”可知，本句应该是“不可能是她。”故排除AB；“不可能”是can’t。mustn’t表示“禁止做”故与题意不符。所以本题选D。