that is the horse which won the race.这里的which可以省略吗

Question

如题，为什么？

Answer 1

which
不能省略。这是一个引导限制性定语从句。
关于which引导从句的小结：
关系代词
which
一般指物，在定语从句中作主语、宾语或定语，既可引导限制性定语从句，又可引导非限制性定语从句。
1.
引导限制性定语从句
如：This
is
the
family
which
is
planning
to
move
to
the
city.
这是要搬进城里的一家。
2.
引导非限制性定语从句。
（
1
）用来指代一个句子。
Internet
is
so
interesting,
which
makes
all
possible
happen.
因特网是如此有趣，它使任何事都有可能发生。
（
2
）用来指代句子的一部分。
When
deep
in
thought,
which
he
often
was,
he
would
forget
all
around
him.
他常常陷入沉思，这时他就会忘掉周围的一切。
（
3
）如果要引导两个非限制性定语从句，第二个
which
前要加
and.
He
bought
a
book,
which
was
written
by
LuXun,
and
which
he
decided
to
give
to
his
friend.
他买了本鲁迅写的书，他决定送给朋友。

Answer 2

不可省略，因为which在定语从句中指代horse做主语

Answer 3

which
不能省略