50 dollars前为什么加It is

50 dollars前为什么加It is dollars后为什么加的是is This is the ring on which she spent 1000 dollars.为什么which前加on?为何这么用? here is 50 dollars,有错吗,为什么不是here are? It is very kind of you to help me的help前为什么要加to It is fun to have ice cream in summerice cream前为什么不加an It is up to you to make a right choice.make 前It is up to you to make a right choice.make 前为什么要加to when is the bank open?it is open in 8am其中open前为什么要加is.还是应回答it open in 8am 省掉is what is this in english?可以回答是it is a telephone.telephone前为什么不加a five dollars 后面加动词be 是加is 还是加 are为什么?是就这么规定的吗?正确答案是is我就是不知道为什么？ It is better to stay at home than to ____(go) out.为什么go前加to Is dinner ready?It's nearly ready.为什么dinner前不用加the?这里不应该用特指吗? It seems that she is very sad=She is seems to be very sad.吗好多人说不能在seem前加is,为什么? 5 dollars is enough 为什么用is dollars 是复数啊 —______ is it? —20 dollars. 填什么. This watch is 100 dollars.It’s a good p_________. 补全对话How much is it?25 dollars ( ) It's good exercise.为什么good前不用加a?