else if symbol

例句：

1. 1. If you don't pass the exam, there will be no other choice but to retake the test.
   如果你不通过考试，别无选择，只能重考。
2. 2. The teacher asked us to solve the problem with the help of a symbol.
   老师要求我们用一个符号来帮助解决问题。
3. 3. The symbol is used to indicate that something is not allowed.
   这个符号用来表示某事不允许。