4. ashamed
adj.感到羞耻的；感到惭愧的（常作表语)
常用结构：
be/feel ashamed of (doing) sth./sb./oneself
为做某事/某人/某人自己而感到惭愧
be ashamed to be/to do sth.   因难为情而不愿意做……
be ashamed that ...  为……而感到惭愧或羞耻
be ashamed for sb.  替某人感到惭愧
I behaved badly yesterday and I am ashamed (of myself) now.
我昨天表现得不好，现在感到很惭愧。
She was ashamed to ask such a simple question.
她不好意思提这么简单的问题。
易混辨析：ashamed/shameful/shameless
ashamed  指事情使人感到羞耻，惭愧，难为情等。
shameful  指事情或行为本身不道德。
Shameless  指某人或行为是可耻的。高手过招
5. effect
n. 结果，效力；作用；影响(后接on/upon)
I tried to persuade him, but with little effect.
我尽力劝他，但他根本不听。
An effect presupposes a cause.
有果必有因。
常用结构：
have an effect on=have an influence on=have an impact on  对……有影响
put/bring/carry ...into effect  付诸实施
in effect  事实上；实际上
take effect  生效；奏效
come into effect  开始实施;开始生效
This had a great effect upon the future of both mother and son.这对母子俩的将来影响很大。
The medicine began to take effect.药力开始生效了。
6. risk
n. 冒险；风险
vt. 冒……风险； 冒……的风险
常用结构：
at risk  处于危险之中
at all risks=at any risk  无论冒什么险;无论如何
at one’s own risk  由自己负责,自担风险
at the risk of doing sth.  冒着……的危险
risk one’s life  冒生命危险
run/take a risk/risks  冒风险
run the risk of doing sth. 冒着……的风险
risk doing sth.  冒险做……
If you don’t obey me, you should be at your own risk.
你如果不服从我的话，你应该自担风险。
They knew they risked being arrested.
他们知道自己冒着被捕的危险。