— What does your mother do, Li Jie?

— She is a (an)        . She teaches (教书) in a high school.

关于美国工业由东北部向南部发展的原因错误的是（　　）

蝗虫适于陆地生活，其形态结构特点有（　　）

①用气管呼吸  ②胸部有三对足，两对翅  ③有外骨骼，防止水分蒸发  ④有一对复眼和三个单眼．

阅读理解

                                                                                               秋夜将晓出篱门迎凉有感

                                                                                                      【宋】陆游

                                                                                         三万里河东入海，五千仞岳上摩天。

                                                                                         遗民泪尽胡尘里，南望王师又一年。

Mother Duck sits________ the eggs. (   )