It must be ascertained if the land is still owned by the government.

必须确定这块土地是否仍属于政府所有。

Once they had ascertained that he was not a spy, they agreed to release him.

一查明他不是间谍，他们就同意了释放他。

I ascertained that the driver was not badly hurt.

我已查清，驾驶员伤势不重。

It should be ascertained that the plans comply with the law.

须要弄清楚，这些计划要合法。

I ascertained that he was dead.

我确定他死了。