Anna is a Chinese girl . She is ten . She is in London with her parents. She doesn't know much English. She can't speak English well. Sometimes her friends don't understand her .

    It's Sunday morning .She is going to the zoo to see the panda . She is waiting at a bus stop .At the bus stop she asks a boy how to go to the zoo. But the boy can't understand her .Then she takes out a pen and some paper. She draw a panda on it and shows the picture to the boy .The boy smiles and then shows her the way to the zoo.

My eyes ____ (is/are) red.

下图是两个生态系统中腐殖质总量随时间而发生变化的情况，甲、乙曲线分别代表哪两个生态系统（    ）