1.give sb. a call 给某人打电话。也可以说成:give a call to sb.
If you are in trouble, give me a call/give a call to me.
如果你有麻烦,给我打个电话。
2. hound v.追逼; 紧追
She was hounded by the press.
她受到记者的追踪。
【常用短语】hound sb on 嗾使某人, 煽动某人
3.be aware of 知道……, 意识到……
John has been aware of having done something wrong.
约翰已意识到自己做错了事情。
4. back out 退出
The bank back out of the contract.
银行终止该项合同。
5. a piece of work 难事。字面意思“你真是个难题”,引申义指Chris不好应付。