When he came back three hours later, they were still ____on the sofa, _____ in conversation.

A．sitting ; absorbing

B．sitting ; to absorb

C．seated ; absorbed

D．seated ; to be absorbed

高纬度地区的范围是（　　）

A．0°-30

B．30°-60°

C．60°-90°

D．23.5°-66.5