一百周年前的世界，动荡与变革并行。下列事件发生在那一年的有（    ）

①中国参与第一次世界大战         ②俄国爆发了“十月革命”

③胡适发起文学改良运动           ④罗斯福实行新政改革

使“秀才不出门，便知天下事”成为现实的是（    ）

    After ____ an hour, Ted and Jenny sat ____ to relax. At that time, they saw a squirrel（松鼠）____ a pine nut (松子）in a big tree. When they saw the squirrel eating, they felt ____. They went to help their parents take the food out of the basket. Ted had a hamburger. Hamburgers were his favorite food. Jenny had an apple. Mr. and Mrs. White had some bread. They ____ in the park.

盒中装有形状，大小完全相同的5个球，其中红色球3个，黄色球2个，若从中随机取出2个球，已知其中一个为红色，则另一个为黄色的概率为（    ）