单项选择题
A．Rooster, eraser, color, truck , mail B．Vacation, iii, travelled, licence, center C．Mail, traveled, sick, color, license D．Sick, truck, color, rooster, post
A．it isn't necessary to know their differences B．there are only a few differences in spoken English C．it will be difficult for others to understand you D．it's hard to remember the differences at the same time
A．There are many names all over the world. B．The names in different countries are different. C．Some names are very long, and some are very short. D．Some people have nicknames.