Yet it can take a lot of time just to choose the right one.

如上句， 还能详细说说just的用法吗？

adv.（副词）

Precisely; exactly:
精确地；正好，恰恰正是：
just enough salt.
正好足够的盐
Only a moment ago:
刚才，方才：
He just arrived.
他刚刚到达
By a narrow margin; barely:
勉强地，差一点就不：
just missed being hit; just caught the bus before it pulled away.
差点被击中；及时搭上即将启动的公共汽车
At a little distance:
距离不远地：
just down the road.
就在马路那头
Merely; only:
只，仅仅：
just a scratch.
只是一道刮痕
Simply; certainly:
完全地，简直：
It's just beautiful!

你的那句中的 just 是副词，意思是： 只，仅仅。