back /bæk/ adv.向后
He turned and looked back.
他转身向后望。
Don't look back.
不要向后看。
Please step back.
请退后一步。
I fell back.
我向后跌倒。
back /bæk/ adv.回
She could no longer hold back her tears.
她再也无法控制住眼泪。
Please give me my ball back.
请把我的球还给我。
If he kicks me,I'll kick him back.
他要是踢我，我就踢他。
Put the book back on the shelf.
把书放回书架上。
He'll be back on Monday.
他星期一会回来。
I can't wait to get back home.
我迫不及待想赶回家。
Could you call back tomorrow.
明天你能回电话吗？
back /bæk/ v. 支持
All sides back the peace plan.
各方都支持和平计划。
back...up 支持/支援；证实（某人所言）
I always back you up.
我一直支持你。
I'll back you up if they don't believe you.
如果他们不相信你，我会为你作证。
I need you to back me up.
我需要你的支持。
Back up your opinions with examples.
用例子来支持比的观点。
back /bæk/ v. 后退
He backed against the wall.
他退到墙边。
You can back your car in.
你可以倒车进去。
The horse backed suddenly.
马突然向后退。
back /bæk/ n.后部 背部
back pain 背痛
turn one's back 背过身去
There's room for three pepole in back.
后排有可容三人的空位。
the back of the paper 纸张背面
Do you sleep on your back or your front?
你睡觉是仰着还是趴着？
He stood with his back to the door.
他背对着门站着。
Write your name on the back of the paper.
把你的名字写在纸张的背面。
back /bæk/ adj.后面的
① 表示位置后面
back seat 汽车后座
back teeth 臼齿
② 抽象意义的后面，引申为“拖欠的”
back pay /taxes
拖欠的薪水/税
His house has a back garden.
他家有一个后花园。
There is no light on the back wall.
后面的墙上没有灯。
We are sitting in the back row.
我们坐在后排。
back rent
拖欠的租金
以上引自灶灶大师兄的躺学语境，如有侵权，联系删除！