中国恢复在联合国的一切合法权利是在（    ）

圆内接四边形ABCD中，$\angle A$、$\angle B$、$\angle C$的度数比是$2:3:6$，则$\angle D=$（  ）．

阅读下列短文，从每小题的三个选项中选出最佳选项。

    It's autumn. It's cool and windy. Charlie is flying a kite in the park. His father is watching(观看).The kite is flying high(高) in the sky. They are happy. Look! The kite is not in the sky now. Where is it? Oh, it's in a tree. Charlie is sad. Charlie jumps and jumps. The tree is tall but he is short. He cannot get(拿到) the kite. Charlie's father is not very tall but he is clever(聪明的). Look, he is on a car. He can get the kite for Charlie. Charlie is happy.

①看电视时将音量、亮度适当调小，关机后拔掉电源插头；

②用照明效果相当的高效节能灯代替白炽电灯；

③冬天，饮水机的加热开关一直闭合，以便随时都有开水喝；

④电冰箱里准备食用的冷冻食物提前放入冷藏室熔化；

⑤打开工作中的冰箱门来降低室温；

⑥离开房间时随手关灯；

⑦推广使用太阳能热水器．