A:邀请中国乒乓球队访美,开展乒乓外交
B:表达总统访华意愿,改善中美关系
C:签订《中美联合公报》,结束中美对抗关系
D:就日内瓦会议的问题与中国进行谈判
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.
用微粒的观点解释下列事实.
(1)碘固体(I2)和碘蒸气都能使淀粉变蓝.
(2)等质量的碘固体和碘蒸气比较,碘蒸气的体积远大于碘固体.