求援的英文：
reinforce

参考例句：

frantic gesticulations in an attempt to get help
试图求援的狂乱的比手画脚

He appealed to me for help.
他向我求援。

They applied to him for help.
他们向他求援。

They also applied to other medical institutions for assistance.
他们也向其他医疗机构求援。

The governor concluded not to call for aid from other countries.
总督决定不向其他国家求援。

Help was lacking at sea during the storm
起风暴时海上无处可求援。

At last to go forth together and seek help in the neighbouring hamlet.
我们最后决定一起去附近的村子求援。

If any disinterested persons are present, he turns to them for some reinforcement of his own faltering mind
若有不偏不倚的人在场，他就会求援于他们，以稳定自己动摇不定的思想。

reinforce是什么意思：
v. 加强，加固；强化；补充
n. 加强；加固物；加固材料

The designer chooses the layout of reinforcement.
设计者选择钢筋布局。

Will you take measures to reinforce them?
有加固措施吗？

They had to reinforce the center.
他们必须加强中央的权威。

That concrete is reinforced with steel beams.
那混凝土是用钢筋加固的。

This roof needs some reinforcement.
这屋顶需要加固。