below 20 per cent, its bactericidal action is negligible.
浓度低于20％时，杀菌能力基本上就不存在了。
新概念英语第四册 Lesson 38 Water and the traveller

📚 句中词汇解析

从本句中提取的重要词汇

below [bɪ'lo] 词频1
adv. 在下面，到下面; prep. （表示位置）在…下面;（表示状态）在…掩饰之下;（表示比较）不及;低于;
💡 be构成一些介词+low低的→在…下面
"He dived below the surface of the water."
他潜入了水中。
近义：infra, under, underneath, beneath 反义：above, over, up, atop, onto, upon
negligible ['nɛɡlɪdʒəbl] 词根: neg
adj. 可以忽略的;微不足道的;无足轻重的;不足轻重;
💡 neg否认+lig选择+ible可...的→不用选择的→可以忽视的
"The cost was negligible."
费用不大，无关紧要。
近义：inconsequential, inconsiderable, insignificant, meaningless, measly, niggling
cent [sent] 词频1 词根: centi
n. 分;一分钱的硬币;零钱;（作单位的）百;
"He drained his parents of every cent they had."
他把父母所有的钱都耗尽了.
近义：hundredth, penny
action ['ækʃən] 词频1 词根: ion
n. 行动，活动;功能，作用;手段;[法]诉讼;
💡 后缀:ion 构成抽象名词,表示行为,行为的结果
"The time has come for action if these beautiful animals are to survive."
若要使这些美丽的动物能生存下去，现在就要行动起来。
近义：movement, advance, implement, start, activate, proceeding 反义：inactivity, ineffectiveness, inertia, rest, inactiveness
bactericidal
a. 杀菌的\\n[医] 杀菌的
近义：sanitizing, antiseptic, cleaning, germicidal, antibacterial

📚 更多「新概念英语第四册」例句

Every solid object will reflect a sound, varying according to the size and nature of the object.
任何固体者反射声音，反射的声音因物体的大小和性质的不同而不同。
he is lending the bank money, repayment of which he may demand at any time,
就等于把钱借给了银行。这笔钱他可以随时提取，
the study was known as Project Anehin.
安内英工程"。
The remains of plants and animals that lived on land are much more rarely preserved, for there is seldom anything to cover them over.
曾在陆地上生活过的动植物的遗体被保存下来的更为罕见，因为陆地上几乎没有什么东西覆盖它们。
Before very long the parents will be complaining that the child is so secretive and never tells them anything,
不要很久，家长就会抱怨孩子守口如瓶，什么事也不告诉他们，
and when he flirts with fame, he is taking time off from living with himself,
当他沽名钓誉时，他就脱离了自我生活，