① How does Amy feel? ____     A. I went swimming．

② What did you do last weekend? ____     B. He is a teacher．

③ Where does John come from? ____     C. He comes from the USA．

④ What's your father's job? ____     D. We have English and music．

⑤ What do you have on Mondays? ____     E. She is tired．

⑥ What is the tiger doing? ____     F. Please hold on．

⑦What will you do for your mum? ____     G. At 7: 00 a．m．

⑧Whose dog is it? ____     H. I'll cook noodles for her．

⑨Can I speak to your mum，please? ____     I. It's walking．

⑩When do you do morning exercises? ____     J. It's hers．

如图2所示的四个情景中，人对物体做功的是（     ）

根据表格内容，选择正确答案。

玉米高茎对矮茎为显性，现在有高茎玉米进行自交，后代既有高茎又有矮茎，比例为3：1。令后代中全部高茎玉米再进行自由交配，则后代高、矮之比为