257. It is no use to _____ the stupidity of his behavior to him, because he will never listen to your advice.
Come and see me whenever ____ .
The invention of steam engine greatly sped up the industrial revolution, which _____ a lot to the take-off of the world.
The quality of a processed food largely ______ the raw material and the way it _______.
—Why is he feeling down today? —Because the suggestion he________has been turned down.
________in his test papers,he didn’t notice my coming.