If I fail to find it, I will get a new book for you.

万一找不到，我只好买一本新的还您。

youdao

It is a trust that --if I fail now --I shall not fail forever;

它是一种信念--如果我现在失败了，那它就是，我不再失败；

youdao

If I fail it will ruin my credibility and I will no longer have a job.

如果我失败了我的信用尽失也没有了工作。

youdao

If I fail,no one will say, 'She doesn't have what it takes,' They will say, 'Women don't have what it takes.'" She made these comments in a speech to the National Press Club in Washington,D.C.

VOA: special.2010.08.08

If you fail to take the test, you get zero, and I average the zero in.

如果你没能参加，那即是零分，我算平均分的时候会加入那个零分。

麻省理工公开课 - 固态化学导论课程节选

If you decide to opt in by a pass fail, I just need to sign your white study card or if you wanna decide before the 5th Monday, just grab the pink slip and I can sign that and you can turn that in at any point and I'm happy to chat during break today or after class if you have any questions or concerns.

如果你上我们的课程只是要一个分数，那么我只需要在你的白卡片上签个名就可以了,或者说，如果在第五周的周一前还没考虑好，把你的解聘书拿来，只要我签个字,任何时候你都开以离开我的教室,当然，如果你有任何问题和疑虑,我也很高心和大家做课下交流。

哈佛公开课 - 计算机科学课程节选

I'll have some fun, and if I fail I'll go do something else.

FORBES: Magazine Article

If I fail my driving test, how long will I have to wait before I can take it again?

FORBES: The New Gov.UK (And The Style Guide Behind It)

If I fail here, I'm pretty much cooked.

FORBES: Life