1. think 

常用替换词如下:(下同)
认为,主张=argue, maintain, hold, believe
考虑=take...into consideration, consider, ponder, meditate, contemplate, think over, reflect on/upon

2. decide 

下结论,断定=come to the conclusion, arrive at the conclusion, draw the conclusion, conclude, judge, assert, wind up

3. get 

获得=acquire, obtain, attain, reap
赢得,取得=earn, gain, procure

4. support 

支持,赞成=approve of, in favor of ,uphold, stand by one's side, agree with, give ones' assent
提倡=advocate, recommend

5. say no to 

反对=oppose, object to, be against
抵制=resist, boycott

6. important 

意义深远的,重大的=far-reaching, profound, significant, eventful
重要的,有决定性的=key, essential, fundamental, crucial, decisive, vial, substantial.
扮演一个重要角色=play an important part in

7. use 

充分运用=optimize, make best/full use of
使用=employ, utilize
应用=apply

8. glad, happy

高兴的,心情好的=be in a good mood, cheerful, joyful, joyous, pleased, delighted

9. hard-working 

勤奋的,勤勉的=diligent, studious, industrious

10. serious 

认真的,谨慎的=conscientious, cautious

11. calm 

冷静的,清醒的=sober, reasonable, sensible, rational

12. clever 

聪明的,有才智的=intelligent, bright, wise, brilliant, smart, ingenious

13. tired 

疲惫不堪的=exhausted, fatigued, run-down, worn-out, weary

14. be used to 

适应=be adapted to, be accustomed to , be adjusted to

15. stop 

阻碍,阻止=hinder, curb, hamper, restrain, prevent, ward off, avoid

16. good side / bad side 

好处,优点=advantage, merit, benefit
坏处,缺点=disadvantage, defect, flaw, drawback, deficiency

17. join

参加=participate in , attend, take part in, go in for, engage in

18. pay one's attention to

集中精力于,专心于=focus on, center on, concentrate on, set one's mind on, be lost in, be occupied in, be attentive on

19. depend on 

依赖,依靠=rely on, lean on