一个初中英语问题We are not sure if it (will rain ) tomorrow. If it (

一个初中英语问题
We are not sure if it (will rain ) tomorrow. If it ( rians ) ,our meeting will be put off.
第二句是条件状语从句,所以用主将从现,第一句不是时间状语从句,所以不用主将从现
这种思维对么

这样的思维是正确的
先看一下if的用法
1.(表示条件)如果 ,主句用将来时,if从句用现在时表示将来
He will come if you invite him.
如果你请他,他会来的.
2.(表示虚拟)假如,要是
1）时态：可以表示过去,现在和将来的情况.它的基本特点是时态退后.
a.同现在事实相反的假设.
句型 ：条件从句 主句
一般过去时 should( would) +动词原形
If they were here,they would help you.
b.表示于过去事实相反的假设.
句型：条件从句 主句
过去完成时 should(would) have+ 过去分词
If she had worked harder,she would have succeeded.
The rice would not have been burnt if you had been more careful.
If my lawyer had been here last Saturday,he would have prevented me from going.
If he had come yesterday,I should / would have told him about it.
含义：He did not come yesterday,so I did not tell him about it.
If he had not been ill and missed many classes,he would have made greater progress.
含义：He was ill and missed many lessons,so he did not make greater progress.
c.表示对将来的假想
句型：条件从句 主句
一般过去时 should+ 动词原形
were+ 不定式 would + 动词原形
should+ 动词原形
If you succeeded,everything would be all right.
If you should succeed,everything would be all right.
If you were to succeed,everything would be all right.
3.是否 = whether 连接宾语从句
I wonder if she is ill.
不知她是否病了.
就这连两个句子来说
If it ( rians ) ,our meeting will be put off.属于上面用法的第一种情况,(表示条件)如果 ,主句用将来时,if从句用现在时表示将来（即主将从现）
We are not sure if it (will rain ) tomorrow 属于上面用法的第三种情况,是否 = whether 连接宾语从句
不清楚的地方请继续发问!