C（21组）
1. care n./v. 小心, 关心, 照顾
When I was ill, my mother always took good care of me.
careful adj.小心的, 仔细的
carefully adv. 仔细地
carefulness n. 细心
careless adj. 粗心的, 随便的
You did your homework carelessly.
carelessness n. 粗心大意
2. celebrate v. 庆祝
celebration n. 庆祝(会), 庆典
3. centre n. 中心，中央
central adj. 中心的，中央的
The central park is opposite the bookstore
4. challenge v. 向……挑战
challenging adj. 具有挑战性的
This is a challenging problem.
5. child n. 儿童，孩子
children(复数) n. 孩子们
Children like watching cartoons.
childhood n. 童年, 幼年时代
l Have an unforgettable childhood.
6. colour n. 颜色, 色彩
colourful adj. 色彩丰富的
7. communicate v. 交往, 交际, 传达
communication n. 交际, 交流, 通讯
8. compete vi. 竞争, 对抗, 比赛
competitor n. 对手, 竞赛者
competition n. 竞争, 比赛
On the sports field, the athletes‘ competition is very fierce.
9.confident adj. 自信的,有信心的confidence n.自信；信心
confidently adv. 自负, 自信地
He has enough confidence to take the college entrance examination.
He has enough confidence to take the college entrance examination
confidence n. 信任, 信心
10. consider v. 考虑, 细想
considerate adj. 体贴的. 周到的
consideration n. 考虑, 体谅
In case of any problem, we should seriously consider it.
11. correct v. 改正, 修改adj. 正确的，恰当的
correctly adv. 正确地，正当地
correction n. 改正，修正
incorrect adj. 不正确的，错误的
12. crowd n. 人群v. 拥挤，挤
crowded adj. 拥挤的
The little boy found her mother in the crowded people.
13. culture n,. 文化，文明，修养
cultural adj. 文化上的，文明的
culturally adv. 文化上，文明地
14. curious adj. 好奇的
curiously adv. 好奇地，奇妙地
curiosity n. 好奇心，求知欲
Children use their curiosity to explore the outside world.
15. chemist n. 化学家
Xiaoming wants to be a chemist when he grows up.
chemical adj. 化学的
We need to solve this problem chemically.
chemistry n. 化学
Chemistry is a very interesting subject.
16. certain adj 当然的，有把握的
certainly adv. 肯定地, 有把握地
17. choose v. 选择
I choose to travel to Qinghai.
choice n. 选择
After some thinking, he finally made the right choice.
18. conclude v. 推断, 总结
conclusion n. 结论，总结
After many experiments, he finally came to the correct conclusion.
conclusive adj. 决定性的
19. complete v. 完成adj. 完全的，完整
completely adv. 完全地，完整地
20. connect v. 联系，连接
After graduating from high school, students seldom connact.
connection n. 联系，连接
21. comfort v. 安慰
Every time I fail in the exam, my mother always comforts me.
comfortable adj. 舒适的，舒服的
comfortably adv. 舒适地，舒服地
uncomfortable adj. 不舒服的
The environment here is very uncomfortable