记忆技巧：con 加强 + stant 站，立 → 一直站着 → 不变的
1.She suggests that women are under constant pressure to be abnormally thin
2.The average speed of the winds remained constant.
3.In the world of fashion it sometimes seems that the only constant is ceaseless change
4.Inflation is a constant threat
5.He has been her constant companion for the last four months.
1.Keep the chemicals at a constant temperature.
2.Her constant nagging drives me crazy.
3.The seeing eye dog was the blind man's constant companion.
1.In our world nothing seems constant.
2.In history, change is constant.
3.He alone remained constant.
S+be+constant+ prep .-phrase
1.They were constant in friendship.
1.He is constant to his friend.
constant friend 忠实的朋友
constant nagging 不停地唠叨
constant temperature 恒温
be constant in〔to〕 friendship 对友谊忠贞
1.Indoor pollution, which includes sources like home heating and cooking, has remained constant over the past several decades despite advances in the area.
2018年12月四级真题（第一套）阅读 Section A
2.Some desalination plants exist where feasible, but they are costly to run and can need constant repairs.
2018年12月四级真题（第一套）阅读 Section C
3.By running constant deficits, it is dis-saving, even as households save more.
4.At heights of over 18000 feet, people may be climbing in a constant daze（恍惚）.
5.They believe, for example, that their employees need constant supervision if they are to work effectively, or that decisions must be imposed from above without consultation.
2016年高考英语上海卷 完形填空 原文
6.Thus humans who lived a million years ago, despite their big brains and sharp stone tools, lived in constant fear of meat-eating animals.
2019年高考英语江苏卷 阅读理解 任务型阅读 原文
7.Vanity is a constant; people will only start shopping more sustainability when they can't afford not to.
2013年考研真题（英语一）阅读理解 Section Ⅱ
8.You may have a circle of friends who provide constant good humor, help and companionship.
2015年考研真题（英语二）阅读理解 Section Ⅱ