可以放在句首吗如Yest it is incorrect.这样说是否正确?yet后是否要加逗号

可以放在句首吗如Yest it is incorrect.这样说是否正确?yet后是否要加逗号 I do not know if it is polite or not to speak loudy at table.句中的or not可以放在whether 之后或句末 Now it is on a flower.改一般疑问句,Now还可以放在开头吗? Though the price of the camera is OK,I don't think I'll take it.Though the price of the camera is OK,____I don't think I'll take it.A.but B.and C.yetD.so 你们说是用C,可答案上是B,B不可以吗,C可以放在句首吗? The life I have is yours.It's yours.It's yours 为什么The life 要放在I的前面 I don't know what exactly it is.这句话对吗?exactly 应放在什么位置? i wonder if it is because I haven‘t been able to be outdoors中outdoors的用法是什么Outdoors是副词,为什么会放在be后面 turn it up的链接可以在空间放的 who is it is me .It is I也对为什么It is I是在资料书上看到的 I think it is sure可以这么用么? _____ we can't join in the party.A.It is a pity B.That is a pity C.It is a pity that 这题为什么选C?that 在主语从句中不是可以省略的么那是that放在句首的情况 如果用it作形式主语 that放后面 那就可以省略的 What time is it?What time is it?后面的is it可以连读吗?是不是读成【i zi t】 it 放在pay for的前面还是后面?如：I pay for it.还是 I pay it for? I study English often.often可以放在句尾吗? it is completely dark down there .for no sunlight can reach the depths of the sea句子中的 for 不放在句子中可以吗, It was exactly what I needed.这里的副词修饰哪个词的 副词的位置可以放在最后么 the weather today is worse than it was yesterday这句话为什么用it was yesterday?the weather today is worse than it was yesterday.为什么最后是It was yesterday呢?它（天气）是昨天.感觉很别扭啊为什么不能写成是：it yest “It is not,however,always a smooth and safe one.”中however是什么用法,为什么放在句子中间,放在句首可以吗?为什么与中文的说法不同?