Mr.King is English这句话为什么对的？

B. The twin is a French
应该改为the twins are French意思为这对双胞胎是法国人,双胞胎两个人所以要用are
C.Mrs.Smith is America
应该改为Mrs.Smith is an American
D.That old woman is an English
应该改为That old woman is English /或者That old woman is an English woman.也正确

英国人(个体)用English man/woman,所以前面要加惯词
而English是英国人(整体)不用加惯词

举个例子Chinese English都是表示整体的词汇，作名词时不能用不定冠词修饰
Andy is Chinese. Carl is English
或者Andy is a Chinese boy. Carl is an English boy 都对
所以A正确

c- not correct she is an american
b- not correct twins are french
d- old lady is english correct

A is correct

A.English:

adj.
英文的, 英国人的, 英格兰的
n.
英国人, 英语

这句话翻译成:Mr.king这个单词是英语

B.我们应该说The twins are French

C.America:美国
American:美国人
所以C项应该改为 Mrs.Smith is an American
D-我们应该说That old lady is an English

应该选A
因为：
B-我们应该说The twins are French
C-我们应该说Mrs.Smith is an Americ