Definition: the usual way something is Level: B2
这条规则有个例外。
There is an exception to this ___rule.
我通常周日去看望父母。
I visit my parents on Sunday, as a ___rule.
通常，骑自行车的孩子长大后常常会换用汽车。
As a ___rule, children who ride bikes often switch to cars as they grow older.
