I am an America(n) boy.用America还是American?

I am an America(n) boy.用America还是American? I come from America.i come from America.I am from America,I am an American.有什么区别? I AM AMERICA怎么样 I am from A________ 选择A、Australia B、America I come from ____ .I am an ____.应该选England；English还是America；American I am ( ) student A:a B:an 等差数列{an}中,am+n=A,am-n=B(m>n),求an 英语选择：I ___ from America.选项：A.am B.am come C.comes D.am coming I am from America(对 America提问） ----- ----- -----from?I am from America(对 America提问）----- ----- -----from? I am from America 翻译成中文 I am from America的否定句 I am a America 是不是正确的 选择题：1、I am an （ ) girl. A. America B.Canada C.China D.American2、I like ( ) the best. A.travel B.traveling C.trip D.shopping 我要考试了,只有两天,快一点,谢谢! 等差数列（An）中,am+n=A,am-n=B,求Am 若｛an｝是等差数列,am+n=A,am-n=B,求am. I come from --.I'm an ---.A America,American B.England,English C.Japan,Japanese I am going to America和I am going to go to America有什么区别? I am an elephant