The train at present speed until it reaches Beijing.A. is runningB. will be runningC. wil

问题补充：

The train at present speed until it reaches Beijing.

A. is running

B. will be running

C. will have run

D. has run

答案：

A. is running

(答案→)B. will be running

C. will have run

D. has run

解析：考查时态。句意：火车将以目前的速度运行直到抵达北京。结合语境可知本句描述的接下来正在进行的动作，故用将来进行时态，选B。