每日一句是
We went rock climbing at the weekend. I loved it, but my friend refused to try it. He’s got a real yellow streak.
我们周末去攀岩了。我爱攀岩，但我的朋友拒绝尝试。他真是胆小如鼠。
讲解：
如果说某人 has a yellow streak, 那意思就是此人比较胆怯、不勇敢。
如果一个人 has a mean streak, 那此人会经常做出卑劣、尖酸刻薄的事情。
My boss won't give me a pay rise - he's got a real mean streak.
我老板才不会给我加薪呢，他实在是吝啬。
