题干
— Mum, we're going to visit an old town this weekend.
— ________!
A：Have a good trip
B：That's OK
C：Not at all
D：Goodbye
答案(点此获取答案解析）
A
— Mum, we're going to visit an old town this weekend.
— ________!
A：Have a good trip
B：That's OK
C：Not at all
D：Goodbye
=2x＋1250，若用水量为 50kg时，预计的某种产品的产量是（ ）