英语语法be动词问题选择正确的答案填空：1.This postcard () great!(is,are)Yes,().

英语语法be动词问题选择正确的答案填空：1.This postcard () great!(is,are)Yes,().(it is,they are)2.These stamps () beautiful!(is,are)Yes,().(it is,they)3.How big () they?(is,are)4.How long () it?(is,are)5.() a map of China,(It's,They're)6.() a picture of the Great Wall.(It's,They're)