■ bow and arrow

“弓箭”如果理解为一种武器的整体，作为主语时动词用单数。

• The bow and arrow was invented at that time.弓箭是那个时候发明的。

• compared
• competition
• competitive
• compile
• compile 与 compose
• complement
• complement 与 compliment
• complex
• complex 与 complicated
• complicated
• compliment
• comply
• compose
• composed
• comprise
• compromise
• comptroller
• computer
• concern
• concert
• condition
• conference
• confess
• confidence
• conflicted