Do you know ________ girl in pink on the playground — Oh, yes, she is ________ honest student. She is my best friend.

下列词语中，没有错别字的一项是( )

There’s no doubt _____enough concern must be paid tothe problem of the stay­at­home children.

Nuclear science should be developed to benefit people _____ harm them[ ]

My friend has achieved his goal after years of hard work.— Great! ______.