have a flu 和have the flu的区别

One of the office girls was down with the flu.

一位女职员得了流感。

Three members of the band went down with flu.

这个乐队有3名成员得了流感。

The school was closed because of the flu.

因为流行性感冒全校停止上课。

I caught a flu and had to lie in the bed.

我得了流感，不得不卧床休息。