If people or things walk or move abreast, they are next to each other, side by side, and facing in the same direction.
The steep pavement was too narrow for them to walk abreast.
这个很陡的人行道窄得不能让他们并排走。
abreast of
If you keep abreast of a subject, you know all the most recent facts about it.
He will be keeping abreast of the news.
他会不断及时了解最新消息。