Our guide，who was a French Canadian，was an excellent cook.
My gardener，who is very pessimistic，says that there will be no apples this year.
如:Peter, whom you met in London, is now back in Paris.
Mr Smith，from whom I have learned a lot，is a famous scientist.
如:The boy,whose father is an engineer, studies very hard.
Above the trees are the mountains, whose magnificence the river faithfully reflects on the surface.
The play，whose style is rigidly formal，is typical of the period.
如:These apple trees，which I planted three years ago，have not borne any fruit.
She is an artist，which I am not.
Water，which is a clear liquid，has many uses.
The two policemen were completely trusted，which in fact they were.
如:She was very patient towards the children，which her husband seldom was.
She is always careless，which we should not be.
如:He said that he had never seen her before，which was not true.
如:In the presence of so many people he was little tense, which was understandable.
He may have acute appendicitis，in which case he will have to be operated on.
When deeply absorbed in work，which he often was，he would forget all about eating and sleeping.
如:He will put off the picnic until May 1st, when he will be free.
如:They went to London，where they lived for six months.
as引出非限定性定语从句时，代替整个主句，对其进行说明但通常用于像as we all know, as it is known, as is known to all, as it is, as is said above, as always mentioned above, as is usual, as is often the case, as is reported in the newspaper等句式中。as在非限定性定语从句中作主语、宾语，且引出的从句位置比较灵活，可位于句首或句末，也可置于主句中间。通常均由逗号将其与主句隔开。as有"正如……，就像……"之意。
如:As is known to the United States, Mark Twain is a great American writer.
He forgot to bring his pen with him, as was often the case.
He is absorbed in work, as he often was.
As we all know, the earth is round.
The two brothers were satisfied with this decision，as was agreed beforehand.
Taiwan is，as you know，an inseparable part of China.
as it is known to all (that...)(as 做状语从句连词，是状语从句, 可以加that)
与 as is known to all(as做主语，是定语从句)
与 it is known to all that...(主语从句，it是形式主语)
即:As is widely known, the moon is closer to the us than the sun.(定从)
= That the moon is closer to the us than the sun is widely known.(主从)
= It is widely known that the moon is closer to the us than the sun.(主从)
As it is known to everyone, I thought you knew about it too.(状从)
They were short of sticks to make frames for the climbing vines，without which the yield would be halved.
They thanked Tom，without whose support they would not have succeeded.
It now has 20，000 hectares of land，more than two-thirds of which are under cultivation.
Light is the fast thing in the world, the speed of which is 300000 kilometer per second.
There are 30 chairs in the small hall, most of which are new.
The textile mill has over 8，000 workers and staffs，eighty per cent of who are women.