问题

Heavy objects and light objects fall at the same speed ________ air holds them back.[ ]

A: so that
B: if
C: unless
D: although

正确答案是：

同类题型

What do you imagine ____________？

Daming, is this your pen— Yes, It’s _______ pen. Thank you!

Uncle Wang taught Jim how thewashing machine.

It’s high time that we students ______ even harder atour lessons as the national entrance examination is coming nearer.

________and angry, Tony rushed out of the room.[ ]