单项选择题
A. useful B. full C. easy D. core
She（）mail the package before the post offic...
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
The seller was trying to sign a substanti...
单项选择题The seller was trying to sign a substantial order（）
A. that is made with certain conditions. B. that you have finalized the delivery dates. C. then he could get a large discount. D. to be more flexible over terms of payment.
They look forward to（）the new products soon...
单项选择题They look forward to（）the new products soon.
A. saw B. see C. seeing D. to see
