The train ___ at the present speed until it reaches the foot of the mountain at about nine o

问题描述:

The train ___ at the present speed until it reaches the foot of the mountain at about nine o
A.went B.is going C.goes D.will be going
如何选择啊?要有解释哦```

选D
句意:火车将以现在这个速度行驶,直到大约九点钟到达山脚为止.
until引导的句子用了一般现在时,说明主句要用一般将来时态.