He took the plunge into the deep end.

他跳入深水区。

He braced himself for the icy plunge into the black water.

他准备跳入冰冷的黑水。

The company is planning a deeper plunge into the commercial market.

这家公司正计划进一步投入商业市场。

That peace often looked like a brief truce before the next plunge into war.

那种和平看起来常常像是投入新一轮战争前的短暂停火期。

She was about to plunge into her story when the phone rang.

她刚要开始大谈她的经历，电话响了。