1.
We must make a clear distinction between right and wrong.
我们必须分清是非。
2.
A friend is a friend, a foe is a foe; one must clearly distinguish a friend from a foe.
敌是敌，友是友，必须分清界限。
3.
A friend is a friend; a foe is a foe; one must be clearly distinguished from the other.
敌是敌， 友是友， 必须分清界限。
4.
We must draw the line Between enemies and friends
我们必须分清敌友。
5.
The industry is full of troublemakers and we must clean them up
该产业中净是捣乱分子，我们必须把他们清除掉。
6.
In particular the threat of Africa's marginalization must be removed.
特别是非洲被排斥在国际社会主流的威胁必须清除。
7.
Oil is absolutely necssary matter for growth of human body and also supplies him with high heat quantity, what is more it is his main origin of aliphatic acid.
油脂是人类赖以生存必不可缺的组成部分，其所含必须脂肪酸和非必须脂肪酸的比例应适当。
8.
The List Source must be a delimited list, or a reference to single row or column.
“列表源”必须是划定分界后的数据清单，或是对单一行或列的引用。
9.
Lists must always start a new paragraph-- that is, they must appear after a blank line.
清单本身必须是段落--也就是，清单之前必须要有空白行。
10.
Pornographic books and periodicals are spiritual refuse and must be removed.
黄色书刊是必须清除的精神"垃圾"。
11.
guards must be good blockers.
前卫必须是一个很好的清道夫。
12.
At this point it should be clear whether the pain is related to the taking of food.
此时，必须弄清楚疼痛是否与进食有关。
13.
We must draw a clear line of demarcation between the two.
我们必须明确地分清这种界限。
14.
The party must be purged of disloyal members at once.
必须马上肃清党内不忠分子。
15.
All debris and detached epidermis must be removed.
一切碎屑和分离的老皮必须清除。
16.
We must resolutely clear out all the bad elements in our society.
我们必须坚决清除社会中的坏分子。
17.
The answers must be intelligible, but they do not have to be in complete sentences.
答案必须要清楚明晰，不过不必是完整的句子。
18.
To bring about such a political situation, we must solve problems inherited from the past and distinguish between right and wrong on major issues.
要实现安定团结、生动活泼的政治局面，必须解决历史的遗留问题，弄清大是大非。