password n 密码
No one could connect our WiFi unless they had a password.
没人能够连接我们的Wifi，除非他们知道密码。
fail the exam 挂科 by the skin of your teeth 侥幸成功，勉强做成 make-up examination 补考
I passed the physical chemistry by the skin of your teeth，but my friend is not lucky,he failed the physical chemistry.He must be ready for make-up examination. 我的物理化学差点挂科了,但是我的朋友就没那么幸运了，他挂了。他必须准备补考
