if we _（bring） a map with us we would know

if we _（bring） a map with us we would know

答案：bring,
翻译：如果我们带着地图，那么我们就知道该走哪一条路了

brought
我们如果带了地图就会知道走哪条路

brought
如果我们随身带着地图，我们就会知道要走哪条路了。

If we had brought a map with us, we would have knew which road to take/If we bring a map with us, we will know which road to take.

如果主句的时态是过去将来时，那么从句要用一般过去时 。例如：
He said that he would have another try if he had the chance.
故此句用brought追答考察内容是主将从现常见的有以下六种情况：
一、如果主句是将来时或表示将来含义时，那么条件和时间状语从句多用一般现在时
如： When I grow up, I will be a nurse and look after patients/ I want to be a nurse and look after patients.
我长大后要当一名护士，照顾病人。
二、如果主句是祈使句，那么从句通常要用一般现在时
如：Don’t laugh at me when I make a mistake.
我犯错误的时候不要笑话我。
三、如果主句是含有情态动词的一般现在时，根据需要从句多用一般现在时
如：You should be quiet when you are in the reading room
在阅览室时应保持安静。
四、 如果if的条件状语从句遇到变换间接和直接时 , 祈使句应用not　to....
如; She said not to close the window
常见的时间状语从句的连词有：as soon as,when,while ,as,until等
五、主将从现说的是在含有时间状语从句和条件状语从句的主从复合句中，如果主句的时态是一般将来时，那么从句要用一般现在时。
例如：I will tell him about it when he comes.
If it is fine tomorrow, we will go outing.
六、如果主句的时态是过去将来时，那么从句要用一般过去时 。例如：
He said that he would have another try if he had the chance.
I knew he could help me if he was free the next day.
主要标志有：if 、unless 、until、 when 、as soon as等

bring,如果我们带着地图，那么我们就知道走哪一条路