请在你的句子末尾加上句号。

Please put a ___period at the end of your sentence.

在缩写 "Dr." 中，句号表示它是 "Doctor" 的缩写。

In the abbreviation "Dr.", the ___period indicates it's short for "Doctor".

句号表示一个句子是完整的。

A ___period shows that a sentence is complete.