I must play my spare time well, or I end up doing nothing.
我必须善于利用空闲的时间,否则生命将会在无所事事中告终。
Up to now, historians have assumed that calendars came into being with the advent of agriculture, for then man was faced with a real need to understand something about the seasons.
历史学家迄今认为日历是随农业的问世而出现的,因为当时人们面临着了解四季的实际需要,