in pursuit or support someone
追求；支持（某人）
to and fro
来回地
in the past; some time ago
在过去，在以前
back in the day, he'd had one of the greatest minds I'd ever come across.
从前他曾是我所遇到过的最有头脑的人之一。
someone's attention is elsewhere
某人的注意力在别处
he kissed her quickly, when the landlady's back was turned.
趁女房东注意别的地方的时候，他很快地吻了她一下。
a very remote or inaccessible place
偏僻处
(Austral. informal)the outback
(澳，非正式)内地
used to express that something is in one's mind but is not consciously thought of or remembered
下意识里
she had a little nagging worry at the back her mind.
下意识里她还存有顾虑。
(Brit.)with the back at the front and the front at the back
(英)前后颠倒
the exhausts had been fitted back to front.
排气管前后装倒了。
a back-to-front baseball cap.
前后颠倒的棒球帽。
reverse the action of the oars, causing a boat to slow down or stop
倒桨
make a wrong or inappropriate choice
下错了赌注；做错了选择
without a person's knowledge and in an unfair or dishonourable way
在某人背后，背着某人
Carla made fun of him behind his back.
卡拉在他背后取笑他。
make someone annoyed or angry
惹恼（或惹怒）某人
(N. Amer.)at the back of something, especially a building
(北美)在后面（尤指建筑）
dad demolished an old shed in back of his barn.
父亲拆掉了仓库后面的一个旧棚。
be entirely familiar with a place or route
（对地方或路线）了如指掌