It is too bad that you missed your flight.
It seems possible that peace will be restored in that country by the end of the year.
Physics,about which I know nothing,doesn’t seem so dull a subject.(定语从句可以转换成I know nothing about physics,可以看出 about 与 know 有关。)
This depends on the purpose for which the examination is given.(定语从句可以转换成the examination is given for ... purpose，介词for与purpose有关。)
This is a phase of history which it is sad to look back on.
The baby whom she is taking care of is very lovely indeed.
There’s a limit (which) nobody should go beyond.
That’s something (which) they can never put up with.
He is the only friend of mine who is not interested in music.
That was the most important day in my life that I can remember.
He laughs best who laughs last.(谁笑到最后谁笑得最好。)
The day will come when you will be proud of me.
There is someone waiting for you outside who says he must see you personally.
There are few places left on earth where man hasn’t put his foot.(4)先行词+定语从句
He is one of those people I know who do not care about money at all.
That is the only film I’ve ever seen which uses that technique.
The suggestion was made that they should be packed off at once in a special train.
Within a week or two he received a letter from the university that he had been accepted.