(1) 长处；实力 strengths and weaknesses 优缺点

(2) 体力；力量 build up one's strength/body 锻炼身体

12. participate vi. ~ in= take part in 参加；参与

　　　　　　　　n. participation (in sth.)

n. participant 参加者， 参与者

区别：participate/ attend / take part in/ join/join sb. in

1) All the Party members attended the conference, at which three other men joined the Party.

2) Shall we join you in your heated discussion?

3) Tom didn't attend_ the lecture because of the private affairs.

4) The old woman took part in/ participated in the student movement actively in his youth.

13. guarantee vt..保证；担保

① guarantee sb. sth. ~ you free entry 保证你免费入场

② guarantee that... We can't ~ that our flights will never be delayed.

③ guarantee to do We ~ to deliver your goods within one week.

n. 保证，保证书 under guarantee 在保修期内

　　　　　　　　　　　　　　　　a year's guarantee 一年的保修期

14. instruct vt. instruct sb. in sth. 教授某人...... ~ us in maths 教我们数学

instruct sb. to do sth. 指示/命令某人做某事

instruct him to come to work earlier / instruct the soldiers to retreat

instruct (sb.) that 告知；通知

I have instructed him that you cannot see him today.

　　　　　　　　n. instruction U 教育， 教授

give ~ in English 教英语

C 命令，指示 ，用法说明， 操作指南，常用复数 .

　　　　　　　　follow ~s 服从指示

　　　　　　　　read the instructions on the bottle阅读瓶子上的说明书

n. instructor 教师；指导者 adj. instructive 有教育意义的