About the quality of 500 cartons of tin food we ordered last time.
是關于我們上次定購的500箱罐頭食品的質量問題。
He is attending a morning intensive course four hours a day, six days a week.
他每周六早晨都上一門4小時的速成課。
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.