spread的过去式和过去分词是什么？

Using too much water could spread the stain.

用水太多可能使污迹扩散。

A series of five interviews will be spread over two days.

一共五次面谈，分两天进行。

The disease is spreading at a rapid rate.

这种疾病正在迅速蔓延。

They took active steps to prevent the spread of the disease.

他们采取积极措施，防止疾病蔓延。

Use of computers spread rapidly during that period.

在那个时期，计算机的应用迅速流传开来。