across与through

The dog walked the street. Then it ran the grass. A through; through B. across; across C. through; across D. across; through 我了解across 是表面横过 through 是立体穿过 。假如这道题就只有前一句的话，也就是The dog walked the street.是否写across或者through 都可以吧？ 但由于有了后一句，所以我理解前一个空是从一边到另一边的横过，所以填across，后一个空也是across。对吗？

The dog walked ______ the street. Then it ran ______ the grass.

A. through; through

B. across; across

C. through; across

D. across; through

答案为 D。非常简单，没障碍的平面（大街；广场），一般用 across；有障碍的地方（森林，人群，草地）一般用 through。

黎老师的例句是 streets（复数），跟本句不同。