She reached the top of the hill and stopped ____ on a big rock by the side of the path.

A．to have rested

B．resting

C．to rest

D．rest

警情之所以能够预报，其根据是（）

A．警度可以测量和评估

B．爆发警情必有一定的先兆

C．客观存在着警源

D．警情会引起人们的警惕