1.impurity n.杂质,不洁,不纯
例句：The water is clear from impurities.
这水干净无杂质。
2.carve v.雕刻,切开,开拓
例句：Please carve me another slice.
请再给我切一片。
3.constantly ad.不变地,不断地,时常地
例句：I am constantly shocked at how little talented people earn.
我常常吃惊为什么有些人才华过人却只挣到很低的收入。
4.gracefully adv.优美地
例句：The girls in this class deport themselves gracefully.
这个班上的女孩举止娴雅。
5.exchange v.交换,调换,兑换;交流,交易
例句：They appointed a place to exchange experience.
他们约定一个地方交流经验。
1.The chemical quality of glass is what makes up its color.
make up弥补,虚构,缝制,整理,包装,和解,编辑,化妆 补足,拼凑,补考
例句：I'll make up a prescription for you.
我给你开一张药方。
He worked overtime to make up for his lateness for work.
他加班以补偿上班迟到。
2.The clay inside is carefully cut out to form a glass container.
cut out故障,停止,开辟,戒掉;剪去,切下;略去,省略
例句：With a few snips she cut out a paper doll.
她几下就剪出一个纸娃娃。
Fold the side seam under and cut out the armhole.
折叠侧缝线并剪下袖窿。
3.Or, he or she can place the hot glass on a metal table called a marver to shape the form by rolling it back and forth.
back and forth来来往往地,来回地
例句：Someone was pacing back and forth behind the curtain.
有人在幕布后踱来踱去。
The dog's tail lashed Back and forth.
狗尾前后摇摆。