Horticulture is the industry and science of plant cultivation.
2.in which, for which, on which, at which的不同用法
The school (that/which) he once studied in is very famous.
= The school in which he once studied is very famous.
Tomorrow I will bring here a magazine (that/which) you asked for.
= Tomorrow I will bring here a magazine for which you asked.
I have a dresser in my bedroom, which there are many cosmetics on.
= I have a dresser in my bedroom on which there are many cosmetics.
The dumpling House which he often has dumplings at is very popular.
= The dumpling House is very popular, at which he often has dumplings.
①The plane may be several hours late, in which case there’s no point in our waiting.
（固定搭配：in the case)
②The speaker paused to examine his notes, at which point a loud crash was heard.
（固定搭配：at the point)
③Ten years of hard work changed her greatly, for which reason he could hardly recognize her at first sight.
（固定搭配：for the reason）
④The film at which I fell asleep was very boring.
（Here "at which" is based on "fell asleep at the film"因为电影无聊而睡觉。）
⑤The little creature in which scientists are interested is known as ET.
（这里"be interested in"是词组原因）
⑥This is the book for which he is looking.
（即等于This is the book which he is looking for，这主要是因为look for 这一短语）
This hall holds a maximum of seventy people.
The maximum temperature in July may be 36 Celsius degree.
We shall derive much benefit from reading good novels.
Anna's strength is derived from her parents and her sisters...
Wind power is an ancient source of energy ______ we may return in near future.
A. in which B. by which
C. to which D. from which