挡土墙适宜的经济高度为( )，一般不宜超过( )。

A．1.0～1.5m；3.0m
B．1.0～1.5m；6.0m
C．1.5～3.0m；6.0m
D．1.5～3.0m；3.0m

---Is your father still in Shanghai?

---Yes, he _________there for two weeks.

A．has gone to

B．has gone

C．has been in

D．has been