湍急的英文：
[Formal] (of currents) rapid; rushing

参考例句：

The subterranean flow is rapid
暗流湍急

The current is running strong.
水流湍急。

Torrential mountain streams;a torrential downpour.
湍急的山溪流;倾盆大雨

The current of the river is fast flowing and treacherous.
这条河水流湍急，变幻莫测。

The little boat kept veering from its course in such a turbulent river.
小船在这湍急的河中总是改变方向。

The raging stream bickered down the valley
湍急的涧水哗啦哗啦地淌下山谷。

The raging stream bickered down the valley.
湍急的涧水哗啦哗啦地淌下山谷。

The river is out of bounds because of strong currents.
这条河现在由于水流湍急,游人禁止入内。

Sammy sniffed sweet smelling sunflower seeds while sitting beside a swift stream.
萨米坐在湍急的溪流边闻着香甜的葵花籽。

She hung on as the freezing, rushing water cascaded past her.
她抓得紧紧的，任凭冰冷湍急的水流从她身上倾泻而下。

formal是什么意思：
adj. 正式的；礼仪上的；有条理的；正规的；公开的 ；拘谨的

You should recast the report in formal wording as it is a formal occasion.
这是一个很郑重的场合，所以你的报告应改的正式一点。

A formal note is essentially a formal personal letter.
正式照会实质上是正式的个人函件。

They are very formal in their business transactions.
他们的商务议事很有条理。

currents是什么意思：
n. （水，气，电）流；趋势，潮流
adj. 现在的；通用的；流行的

erratic current
涡流|不稳定的电流

Stop the current transfer Stop the current transfer (ESC)
停止当前传送停止当前传送(ESC)

A device used to convert direct current into alternating current.
反用换流器用于变直流电为交流电的仪器

rapid是什么意思：
adj. 快速的，急促的
n. 急流

run the rapids.
冲过急流

biological section rapid treater
生物切片快速处理仪

shooting the rapids in a ruBBer raft.
使橡皮充气船快速行驶