1. 你只要打个电话就知道她是否会来了。
You only have to give her a call in order to know whether she will come or not.
2. 我只要去问问老师就能解决这个问题了。
I only have to asd my teacher in order to solve this problem.
3. 你只要买一些报纸就能找到你需要的广告了。
You only have to buy some newspapers in order to get the advertisements that you need.