missing
a.缺掉的，失踪的，找不到的
We found the missing piece of the jigsaw under the chair.我们在椅子下面找到了丢失的那块拼图。
mission
n.使命，任务，天职;代表团，使团
He was sent on over 200 missions before being killed in action.在阵亡之前他奉命执行过 200 多次军事任务。
mixture
n.混合;混合物
the mixture of different people living in the city生活在这座城市里形形色色的人们
necessity
n.必需品;必要(性)，(迫切)需要
She saw books as a necessity, not a luxury.她视书本为必需品而非奢侈品。
negative
a.否定的;消极的;负的 n.底片;负数
My drinking was starting to have a negative effect on my work.喝酒开始对我的工作产生不良影响。
