请帮我检查一下这几个句子有没有错
1。 I am saving up money for a trip to Australia。
2。 It's good (for sb) to eat potato。
It's not good (for sb) to do sth 或者 There is no good doing sth
不说It's no good doing sth
3。 He works hard enough to be a good student。
4。 虚拟语气：
对现在，用过去式；对过去，用过去完成式；对将来，用过去将来式
因此绝对不会出现am, is, are 另外虚拟语气中不能用was
现在...全部
1。 I am saving up money for a trip to Australia。
2。 It's good (for sb) to eat potato。
It's not good (for sb) to do sth 或者 There is no good doing sth
不说It's no good doing sth
3。
He works hard enough to be a good student。
4。 虚拟语气：
对现在，用过去式；对过去，用过去完成式；对将来，用过去将来式
因此绝对不会出现am, is, are 另外虚拟语气中不能用was
现在:If I were tall, mom wouldn't scold me when I eat candy。
过去(给你一个经典例子): If you had told earlier, I would have helped you。
将来:If it were to rain,I could not come back 。
收起
