— My room gets very cold at night.

— ______.

A．So is mine

B．So mine is

C．So does mine

D．So mine does

宇宙飞船在半径为R₁的轨道上运行，变轨后的半径为R₂，R₁＞R₂．宇宙飞船绕地球做匀速圆周运动，则变轨后宇宙飞船的（　　）

A．线速度变小

B．角速度变小

C．周期变大

D．向心加速度变大