根据句意及汉语提示填空。

小题1:Getting up early is a good _______ (习惯).

小题2: Driving carelessly _______ (引起) accidents.

小题3:He isn’t at school now. _______ (或许) he is at home.

小题4: Xu Xiao taught himself on the _______ (互联网).

小题5: We sleep _______ _______ (至少) 8 hours every day.

目前，我国作为城市电源的发电厂以火电厂和( )为主，并正在发展核电厂。

A．风力发电厂

B．水电厂

C．火力发电厂

D．太阳能发电厂