有关定语从句的问题

我想你们在课堂上已经学了定语从句的基本内容。在一开始如果你还不熟练，不妨就先分解出两个简单句来，再根据相应的语法规则构造出定语从句。
比如第6题：
The
seat
is
free.
You
can
take
the
seat.（the
seat是is
free的主语，变成定语从句时用that或which代替，不可以省略，剩余部分照抄。）
→
You
can
take
the
seat
that
/
which
is
free.
（本题是说：你可以坐“任何”一张空的座位。名词前有any等修饰语，就不可用which.
那就是You
can
take
any
seat
that
is
free.）
再如第5题：
He
explained
the
reason
to
us.
This
is
the
reason.（the
reason是动词explain的宾语，变成定语从句时用that或which代替，也可以省略，剩余部分照抄。）
→
This
is
the
reason
(that
/
which)
he
explained
to
us.
如果改一改：
He
didn’t
come
yesterday
for
this
reason.
This
is
the
reason.（the
reason是介词for的宾语，变成定语从句时用which代替，无法省略。）
→
This
is
the
reason
for
which
he
didn’t
come
yesterday.
对于“介词+which”引出的定语从句，可根据语义需要改用when,
where或why.
本句即可说：This
is
the
reason
why
he
didn’t
come
yesterday.
另举两例：
We
visited
the
restaurant
last
week.
This
is
the
restaurant.
→
This
is
the
restaurant
(that
/
which)
we
visited
last
week.
We
had
dinner
in
the
restaurant
last
night.
This
is
the
restaurant.
→
This
is
the
restaurant
in
which
we
had
dinner
last
night.
或This
is
the
restaurant
where
we
had
dinner
last
night.
明白了这一点，再来看第1、第2题：
You
will
spend
the
next
month
in
your
hometown.
Next
month
is
coming.（the
next
month是spend的宾语，在非限制性定语从句中用which代替。）
→
Next
month,
which
you
will
spend
in
your
hometown,
is
coming.
You
will
be
in
your
hometown
next
month.
Next
month
is
coming.（next
month在句中作时间状语，其句法作用相当于以上句子中的for
this
reason和in
the
restaurant，变为定语从句用when代替。）
→
Next
month,
when
you
will
be
in
your
hometown,
is
coming.
不过，“介词+which”被when,
where或why的替换不是无条件的替换。比如第7、第8题。
The
accident
happened
on
the
bus.
This
is
the
bus.（“事故发生在汽车上。”on
the
bus是一个纯地点的概念，或者说是地点状语，构成定语从句既可用on
which又可用where.）
→
This
is
the
bus
(on
which
/
where)
the
accident
happened.
I
came
to
this
town
on
this
bus.
This
is
the
bus.（“我乘这辆车来到城镇。”on
the
bus表示利用这种交通工具，有方式的含义，而不是时间、地点、原因，构成定语从句只可用on
which.）
→
This
is
the
bus
on
which
I
came
to
this
town.
(To
be
continued.)

这里的问题主要是出在most和mostly上面啦。most在这里表示“最”，而mostly表示“大部分，主要”。

同学说的补which的确是可以，但是这里省略which也是可以的。因为先行词city是作定语从句的宾语，这种情况下我们可以省略that，which等词。

如果要改B的话，和楼上同学说的一样，可以改成(which) I like to visit the most.

mostly： 主要地；大部份；大部分；大多，所以mostly不能在这表示“最”的意思。
city前用的是the，表示特指，不能再用which修饰。如果用which，则冠词改用a，“but that’s a city which I like to visit the most。”
最好还是和同学研究一下再问问老师，一起学习的过程将会是你以后甜蜜的回忆哦~~~

most的意思：（与两个或两个以上音节的形容词或副词连用，构成最高级）最
mostly的意思：大部分, 主要地, 多半, 通常, 一般地
所以mostly是意思跟句子搭配不了，只能是most

A中的most是much的最高级形式，做副词，修饰like，没有错误。之所以选A，个人认为是由于B中的which和前面的that重复了。