As he is a good teacher,he often has to whistle up new ideas for lessons.作为一个好老师，他常常要为功课冥思苦想些新招。He had to whistle up some new ideas for lessons.他只好勉强给上课的教材添些新内容。Please whistle up all the dogs quickly.赶快吹哨把狗召回来。He whistled up four or five people to give us a hand.他吹口哨叫来四五个人给我们帮忙。