threaten 

(1)vt.威胁;恐吓( 英文解释:If a person threatens to do something unpleasant to you, or if they threaten you, they say or imply that they will do something unpleasant to you, especially if you do not do what they want.)

结构(1) threaten to do sth威胁要做某事

He said army officers had threatened to destroy the town

他说陆军军官们曾威胁要摧毁那座小镇。

结构(2) threat sb with sth 用某物威胁某人

He tied her up and threatened her with a six-inch knife.

他把她捆起来，拿着一把 6 英寸长的刀子威胁她。

结构(3) threat sb 威胁某人

If you threaten me or use any force, I shall inform the police.

你要是威胁我或是动武，我就报警。

(2)vt.危害到;威胁到(英文解释if something or someone threatens a person or thing, they are likely to harm that person or thing)

结构(1) threaten  sth威胁到某事

The newcomers directly threaten the livelihood of the established workers.

新来的工人直接威胁到老工人的饭碗。

结构(2) sth be threatened  by sb某事遭受到(某人）威胁

The unity of our society is threatened by troublesome and restless minorities.

我们社会的团结遭到了一小撮滋扰生事、不安分守己的群体的威胁。

结构(3) sth be threatened with  sth某物面临(某事)危险

30 percent of reptiles, birds, and fish are currently threatened with extinction.

目前，30% 的爬行动物、鸟类和鱼类面临灭绝的危险。

(3)vt.(坏事)可能发生，将要发生(英文解释： If something unpleasant threatens to happen, it seems likely to happen）

结构(1) threaten  to do sth 可能会做某事

The fighting is threatening to turn into full-scale war.

这场战斗有可能会演变为全面的战争。

Plants must be covered with a leaf-mould or similarly protected if frost threatens.

如果霜冻来临，植物必须盖上腐叶土或用类似方法加以保护。