46.礼品,礼物
present: It shows a friendly and respectful attitude usu substantial things.
gift: It shows something which is given voluntarily given without
expectation of return or compensation.

47.愚蠢
silly: Foolish or childish
a silly boy/story/fellow/question/mistake, silly remarks.
foolish: Very silly or unwise
a foolish act/child/old man, foolish people.
stupid: Showing lack of good judgment¹ or intelligence and not at all
sensible.
a stupid idea/mistake/person/act.

48.地区,地域
zone: A particular part of something or a particular place.
area: A small or large part not thought of a fixed² land division.
A playground is an outside area.
region: Usually part of a country usually large may or may not
be thought of as fixed land division.
A desert is a barren region.
district: A fixed land division usually smaller than region.
We live in Hongkou District of Shanghai.

49.会议 集会
meeting: The most general one. any gathering³ of several or many people in one place at a certain time. A meeting can be large or small, long or shirt. It is usually planned ahead of time.
(年会) convention: An annual meeting of an organization or political group.
(讨论会) conference: A meeting at which two or more people have an formal discussion and exchange views on a subject.
(代表大会) congress: A formal meeting of representatives of societies or countries to exchange information and opinion.
(集会) assembly: A group of people who have gathered together for a meeting for the purpose of being informed, being entertained or making group decisions.
(协商会) council: A meeting of a small group of people chosen from a large group to serve as advisers⁴ or consultants⁵.

50.成就,功绩
achievement: Something which one succeed in doing esp. after a lot of effort usually dangerous or difficult.
The first space flight was a great achievement.
accomplishment⁶: The skill that people have required. It is something that took knowledge and, usually, hard work. When you have solved a hard arithmetic problem or learned to figure out, you can be proud of your accomplishment.
Among his many accomplishments⁷ is the ability to play card tricks.
feat⁸: It requires more courage and strength. It applies to mental acts as well physical acts.
Learning a new skill is a feat.
exploit: An accomplishment that requires even greater daring and heroism⁹ than a feat.
Old stories tell about the exploits of famous heroes.