"Really. When you are a little older you will doubtless learn the advantage of minding your own business. If you will be so good as to turn your head slightly to the left, you will see the door. I wish you good-afternoon."
请教老师: be so good as to do 这是一种什么结构? 其中,这里的as是副词吗? 起什么作用?可否省略as,即be so good to ?我不懂这里的as。