阅读下列短文，从每小题的三个选项中选出最佳答案

      It is morning now. Look at the sun, it rises in the east(东方). Look at the tree, the shadow is long. It is noon now. The sun is high in the sky. It is very hot. Look at the tree. The shadow is short. It is evening now. The sun goes down in the west(西方). Look at the tree, the shadow is long again. It is night now. The moon is high in the sky. There are some stars in the sky too.

豌豆植株中，高（T）对矮（t）是显性，若子代中有25%是矮杆的，则其亲本的基因组成是（    ）

心肌梗塞是一种常见的疾病，严重威胁人的生命，其主要原因是（　　）

A.   B.

C.   D.

台风过境绿色植物倒伏后，它的茎杆前端部分恢复直立状态，引起这种现象的原因是(   )