一般在拔牙后多长时间制作全口义齿最佳（）
A.1个月
B.2个月
C.2～3个月
D.3～4个月
E.6个月
参考答案：C
Read and choose.（根据情景，选择正确的地点写在横线上）
go to school go to restaurant go and see a doctor
go to a theater go to a shop
1. When you want to learn something, you can ________.
2. When you feel hungry, you can _________.
3. When you feel sick, you can _________.
4. When you want to see a film, you can ________.
5. When you want to buy something, you can _________.
1-2+3-4+5-6+7-8+…+1989-1990+1991=_____。
A．895
B．896
C．995
D．996
