Most people are fond of swimming.We must know some rules___water satety in oreder to keep safe.
问题描述：
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.
答
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?