It is essential that we protect our environment.
我們有必要保護我們的環(huán)境。
It is essential that our country trade with other countries.
我們國家與其他國家進行貿(mào)易往來是有必要的。
It is essential that we send the victim to the hospital immediately.
我們有必要馬上送受害者去醫(yī)院。