她去年冬天染上了严重的流感。

She ___contracted a severe flu last winter.

我们公司与那家工厂签订了供货协议。

Our company ___contracted with that factory for the supply agreement.

她在学校感染了流感。

She ___contracted the flu at school.

气球在寒冷的空气中收缩了。

The balloon ___contracted in the cold air.

在非正式写作中，'do not'常被缩写为'don't'。

In informal writing, 'do not' is often ___contracted to 'don't'.