Most people are fond of swimming.We must know some rules___water satety in oreder to keep safe.A of B for C as Dby选什么?为什么?解释详尽些.

选A
of 表示 prep. 关于；属于
for prep. 为，为了；因为；给；对于；至于；适合于
conj 因为
as
conj. 因为；随着；虽然；依照；当…时
prep. 如同；当作；以…的身份
adv. 同样地；和…一样的
by prep. 通过；被；依据；经由；在附近；在……之前
adv. 通过；经过；附近；白俄罗斯
望采纳
上一位看看字典解释
柯林斯高级英汉双解词典
rule/rul/( rules, ruling, ruled )CET4
1. N-COUNTRules are instructions that tell you what you are allowed to do and what you are not allowed to do. 规则
例：...a thirty-two-page pamphlet explaining the rules of basketball.
…一本说明篮球规则的32页的小册子。
2. N-COUNTA rule is a statement telling people what they should do in order to achieve success or a benefit of some kind. 原则; 准则
例：An important rule is to drink plenty of water during any flight.
一条重要的原则是在任何一次飞行中都要喝大量的水。
3. N-COUNTThe rules of something such as a language or a science are statements that describe the way that things usually happen in a particular situation. 规律; 法则
例：...according to the rules of quantum theory. 注意，是of
…根据量子论的法则。

B
rule(s) for 针对…的规则:
There seems to be one rule for the rich and another for the poor.
好像对富人有一套规定,对穷人又另有一套规定似的.
What is the rule for forming plurals?
构成复数的规则是什么?