■ 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。

• fit, fitted, suitable, suited
• fitted
• fix
• flag
• flag 与 banner
• flammable
• flammable 与 inflammable
• flatter
• flee
• flesh
• flesh
• flesh 与 meat
• flight
• floor
• flora
• flourish
• foe
• follow
• following
• fool
• foot
• football
• football 与 soccer
• for
• for