北京人所处时期为原始社会晚期的氏族公社，而山顶洞人所处的时期则是原始社会的早期。
参考答案：错
生物的遗传信息主要储存在 。
Playing QQ’s “Happy Farm” by planting, watering, fertilizing and harvesting vegetables, fruits and flowers, we can find out _______ all the excitement is about.
A．that
B．if
C．when
D．what
