单项选择题
She（）mail the package before the post office closes.
A. has B. have to C. has to D. must to
单项选择题 The seller was trying to sign a substantial order（）
单项选择题 They look forward to（）the new products soon.
单项选择题 The telephone line is（）busy at the moment.
单项选择题 The computerized doll（）the quality test.
单项选择题 We need to consider a couple of options（）
