This is, of necessity, a brief and incomplete account.
这必然是一份简略的、不完全的'描述。
We recognize the necessity for a written agreement.
我们认为有必要签订一份书面协议。
We were discussing the necessity of employing more staff.
我们在讨论是否需要雇用更多员工。
Air-conditioning is an absolute necessity in this climate.
这样的气候绝对需要有空调。
Water is a basic necessity of life.
生命离不开水。