It is和It was是否都可以缩写为It`s

It is和It was是否都可以缩写为It`s It was 可缩写为It's it was可以缩写为 it's吗?看到很多书都写it was,不写it's,什么原因呢? 请问It was 和 It has 可以缩写成It's吗? it was 可以缩写成it's吗? it was可以缩写成it's吗 it’s 可以理解成it was的缩写吗? it was/it has/it is 可不可以缩写?缩写成什麽样子? 强调句it is（was) .that/who,其中it is（was)能不能写成it's/it was不能缩写么? it is缩写 It was 可不可以缩写成 It's it is 缩写Yes,it is 这句话中“it is”可不可以写成缩写 “it's”?如果不可以请说明原因,在什么样的情况下可以用缩写.It isn't a German car.这句话中的“It isn't”和It's not a German car.中的“It's not ” 是不是词组里的单词只要能缩写就可以缩写?比如it is——it's she is—...是不是词组里的单词只要能缩写就可以缩写?比如it is——it's she is—— she's在词组成立的情况下,是不是is都可以写作's? 强调句型it is/was .that 中is/was 是否还可以有其他形式 如has been 等等 哪些单词可以缩写例如：it is=its it is的缩写形式 It is= 的缩写 It is a key缩写