eighth
　　[名　词] (与 the 连用)第八(个), 八分之一.
　　He was the eighth to arrive that island.
　　他是第八位到达那岛上的人.
　　[形容词] 第八的, 第八个的.
　　She gave up on the eighth day.
　　她在第八天放弃了.
　　
 
　　eighty
　　[名　词] 八十, 八十个, 八十人.
　　I was born in nineteen eighty.
　　我出生於 1980 年.
　　[形容词] 八十的, 八十个的, 八十人的.
　　The train is eighty minutes late.
　　这班火车慢了八十分鐘.
　　
 
　　for
　　[介係词] 為了..., 对於….
　　This hat is a little too small for me.
　　这帽子对我来说是小了些.
　　[连接词] 因為, 由於.
　　Mary did not go to school yesterday, for she was sick.
　　玛丽昨天没有去上学, 因為她生病了.
　　
 
　　force
　　[名　词] 力量, 武力, 暴力.
　　You must use force to open that bottle.
　　你必须用力才能打开那个瓶子.
　　[动　词] 强迫, 用力推进, 强行攻佔.
　　Don't force the child to eat.
　　不要强迫这小孩吃东西.
　　
 
　　forty
　　[名　词] 四十, 四十个.
　　She moved to America at the age of forty.
　　她在四十岁时移居美国.
　　[形容词] 四十的, 四十个的.
　　We have forty students in our class.
　　我们的班上有 40 个学生.