在等差数列{an}中，若a3=-1，a7=1，则a11= .
3
.
如图所示是实验室常用的温度计，这种温度计是根据液体的______规律制成的，图中温度计的读数是______℃．
— Sorry indeed, I ______ to your birthday party if…
— Forget it. I know you were out on business. [ ]
A. must come
B. would have come
C. must have come
D. would come
.
.