■ optimistic

应该是指人，不指事物。

• He cited several optimistic factors.他举出了几个令人乐观的因素。

应该改为 He cited several favourable/encouraging factors.

• may
• may
• may not
• may 与 can
• may 与 might
• mean
• mean
• means
• meant
• measure
• meat
• meat
• meat 与 flesh
• media
• median
• medicine
• meet
• meet with
• meet 与 meet with
• memory
• mere
• merit
• method
• middle age
• middle school