依次填入下列各句的成语，最恰当的一组是（ ）①为官很难，因为要想干好事业就要______，倾注心血，甚至“5+2”“白+黑”地加班加点，日夜操劳。②今年因天气影响，双季槐遇到成穗少、大面积减产等问题。雷茂端为此______，正在积极寻求科技突破。③江西省内大大小小200余家老字号，除亨得利、黄庆仁等少数几家著名品牌外，近七成生存困难，______。

The headmaster won’t have students ____cheating in theexam.[ ]

In my ideal school, we have a big library _____ lots of _____books.

We don’t of her going to work in the fields in the sun.

47 Three hundred firemen raced to thehotel after a smoke detector ______ the alarm soon after midnight