1.to be good for
2.to go over to
3.to buck up
4.to come in handy/useful
5.to feel one's oats

1.to be good for 这是一个多意义的成语,造句如下:
1).(有必需的精力,意愿等)能维持...
The old man is good for another 20 years.
那个老头还可干个上20年.
2).有支付能力;愿意支付
He was confident that as far as contributions were concerned his friend would be good for another 100 dollars.
他相信他的朋友还能再拿得出100美元的捐款.
3)能产生...的结果
This problem is good for a debate of another half-year.
这个问题还够辩论半年的.
4).有效
The return ticket is good for another three months.
回程票有效期还有三个月.
5).对...有用(益)
This kind of slippers is good for cold weather.
这种拖鞋适宜寒冷季节穿.

2.to go over to 也是多义成语:
1).受欢迎;成功(不及物)
These actors went over very well with the audiences.
这些演员深受观众们的欢迎.
2).推迟,延期(不及物)
We have no time to deal with this question today, it'll
have to go over to the next session.
今天我们没有时间讲这个问题,得留到下次了.
3).越过;渡过(及物)
They went over the river by ferry.
他们乘渡船过河.
4).浏览;复习(及物)
Before you hand in your composition you'd better go over it. 你最好先把作文好好看一遍再交上来.
5).检查;察看(及物)
After going over the house, he decided to buy it.
他看了一下那幢房子后,决定把它买下来.
6).打量(及物)
She went over the stranger carefully from head to foot.
她审慎从头到脚端详着那位陌生人.

3.to buck up 也是多义成语:
不及物:
1).赶快
Buck up, or you'll miss the train.
赶快,要不你就赶不上火车了.
2).振奋起来
He bucked up at the thought that the assignment could be
fulfilled ahead of time.
一想到可以提前完成任务,他的精神大为振奋.
及物:
3).使...振奋,使...振作起来
He was bucked up by the news that his friend was coming
to visit him.
朋友即将来访的消息使他极为兴奋.

4.to come in handy/useful 可能有用;偶然会有用
I always take this pocket dictionary along as it may come
in handy.
我常把这本袖珍词典带在身边,因为有时要用到它.

5.to feel one's oats
1).兴致勃勃;精神焕发;活跃
When the children got to the park, they were feeling
their oats. 孩子们走进公园时,一个个兴高采烈.
2).自负起来;自鸣得益
You needn't be feeling your oats like that, even if you've achieved a lot in your work.
即使你在工作中取得不少成绩,你也没必要摆出那付洋洋得意的样子.


参考资料:R.C.Goffin: English Idioms and how to use them
Oxford University Press