The police found a white, powdery substance under the suspect's fingernails.
4.sensitive adj. 敏感的；容易受伤的
Don't be so sensitive! They were only joking with you.
5.personality n. 性格
Despite being twin brothers, Tom and Bill have completely different personalities.
6.personally adv. 个人地；亲自地
This package is very important, so please deliver it personally.
7.engage in 参与；从事
Before the merger, both companies engaged in long negotiations to ensure the best deal.
8.behavior n. 行为
The children were on their best behavior while their grandparents were visiting.
9.activist n. 积极分子