since引导的状语从句,后面的谓语动词如果是延续性,那么要解释成如果不吗?为什么?
one of 引导的状语从句用that不用which?为什么?
make a mark where you have doubts 这句话换成make a mark at the place where you have doubts 是对的吧,但这样为什么不对?make a mark at where you have doubts
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1.-----关于since:这个词本身的主要解释有“自从”,“既然”等,词性可用为介词,副词和连词；
你问为什么和延续性动词连用时它不能释为“如果”,这你可以用些实例套一下：
e.g.(1).Many things have changed since the stayed there;
(2).She has been watching that stone since her lover slept in the woods.
...
2.----one of xxx,即,数量一定大于1；当是这种情况时,这不少于2的情况可能会是“人”和/或“事”和/或“物”.鉴于此,用that引导词而不用which；
3.----这里主要分清的还是定语从句和状语从句的问题（就此题讲,这里只对where而言)：定语从句有“先行词”(place)和“关系词(副）”(where=at which)；而在状语从句里,where 是连词,前后连起来的是两个句子.所以"Make a mark at where you have doubts"中去掉at 或在where 前添加一个先行词就正确了.
----3.(2)."Make a mark at where you have doubts"是个含状语从句的复合句式,