1.engage in:take part in.这是一个比较正式的用词，同义词有，participate in,join in

例句 She tried desperately to engage him in conversation

2.deal in :to be interested in or involved in

3.sneer: to show that you have no respect for sb by the expression on your face or by the way you speak.

同义词:mock  搭配:sneer/ mock at

例句:He sneered at people who like pop music.

4.on hand: available,especially to help.现有的帮助

The emergency services were on hand with medical advice.

5.at expense of: with loss or damage to sb.在牺牲或损害……的情况下

He built up his business at expense of his health.