have only to

基本解释

Yet, the neophytes have only to look toward their neighbor South Korea to conclude that the need for reform remains.
然而，刚实行该制度的国家只需要留意一下其邻邦韩国就可以得出结论-改革的必要性依然存在。
That said, most gay Americans above a certain age have only to dip into their memories for proof that their country has grown dramatically more tolerant.
那也就是说，多数基于一定年龄的美国同性恋者仅沉浸在他们的想象中论证自己的国度戏剧性的变得更为包容。
An electronic reading supplies me with a list of the frequencies, which I have only to glance at to form an idea of the problems the book suggests to my critical study.
电子阅读给我的感觉就像是一个频率的列表，我只要瞥一眼这个列表，就能知道这本书对我的研究可能会有怎样的帮助。

At the time, scientists believed that a person at the top of the mountain would only have enough oxygen to sleep.
So I will ask you questions. The only annoying thing I will have to do is to repeat your answers.
所以我要向你们提问,唯一很讨厌的就是我要你们重复你们的回答。
耶鲁公开课 - 1945年后的美国小说课程节选
The only university requirement is, or that I have to take is American Cultures.
学校规定必须选的是美国文化。
关于授课系统 - SpeakingMax英语口语达人

That said, most gay Americans above a certain age have only to dip into their memories for proof that their country has grown dramatically more tolerant.
ECONOMIST: Gay marriage