6,achievement n.①完成，达到(目的)，实现：the achievement of one's object达到目的

　　②成就，成绩，成功：The inventor was rewarded by the government

　　for his scientific achievements.

　　7,acknowledge know 知道

　　vt.①承认，承认…的权威(主张)：acknowledge defeat承认失败

　　②公认为，认为：He was acknowledged as their leader.

　　③致谢，鸣谢：We should acknowledge his services to the town.

　　④告知收到，确认：We must acknowledge his letter.

　　The essat of the famous writer have been acknowledged as major contributions to American literature.

　　8,acquaint

　　vt.(with)认识，相识，了解：I am acquainted with him，but only

　　on a professional basis.

　　9,acquaintance

　　n.①(with)熟悉，熟知，相识，了解：a little acquaintance with English

　　稍微会一点英语

　　②熟人，相识的人：He is an old acquaintance.

　　Should all acquaintance be forgotten?

　　10,acquire quire: 求问，

　　vt.取得，求得，获得，学得：(知识等，后天学)

　　He acquired an appreciation of classical music.

　　Require