中国宇航员____乘神舟五号飞船航天飞行圆满成功，圆了中华民族的“飞天梦”。

阅读下面短文，从短文后所给的A、B、C、D四个选项中选出能填入相应空白处的最佳选项。

    This is an apple tree. There are many 1 on the tree. There are some 2under it, too. They are 3 happily. Under the tree I can 4 a boy and a girl. They're playing games with the dogs.  The boy is 5 a blue sweater and white shoes. He is Jim. He is 6 American student. He is 14. He 7 his school very much. The girl is Jim's sister, 8 name is Cindy. She is 11. She is in a yellow dress. Her shoes are yellow. 9 . Now they are standing here, they are waiting for their friends. They 10 to play games under the tree.

凝固点是0℃，酒精的凝固点是-117℃，小明把酒精和水的混合物放入冰箱的冷冻室（冷冻室温度可达-5℃）中，经过相当长的时间后，从冷冻室取出混合液体时，却发现混合液没有凝固。就这个现象请你提出一个猜想：____ ；根据这一猜想举出一个实际应用的例子____ 。