A. are B. pandas C. fat D. this E. tiger
Ann and Sam are in the zoo.
Ann:What's ____?
Sam:It's a ____. It's big.
Ann:What ____ they?
Sam:They're ____. They're ____.
绿色植物每个细胞都含有线粒体和叶绿体。 ( )
1927年,蒋介石在南京成立国民政府,其性质是( )