Thanks for ______________ us ________ on the school trip.
A:let, go
B:to let, to go
C:letting, go
D:letting, going
138减去42的差是____?73与27的和是____?将所得的差与和相乘,积是____?
北京七月平均气温是26℃,一月是-4.7℃。北京的气温年较差是( )