it's good _ students _ the classroom clean.A for;to keep B of; to keep C of; keeping D for;keep

it's good _ students _ the classroom clean.A for;to keep B of; to keep C of; keeping D for;keep
it's good _ students _ the classroom clean.
A for;to keep B of; to keep C of; keeping D for;keep

it's good _ students _ the classroom clean.A for;to keep B of; to keep C of; keeping D for;keep
A for;to keep

A

A
it's +形容词+for sb to do sth常用句型

前面填for
后面填keeping或to keep都行，
选A

A
it's +形容词+for sb to do sth 表示对某人来说做什么事是怎么样的
it's +形容词+to sb to do sth 能够说明人的性格的形容词可用此句型

A 也可以是 for ; keeping

a 对学生来说保持教室清洁是好的