询问信 Dear ______ , ①I am ______(自我介绍). ②I am writing to see if it is possible for you to provide me with information regarding ______(要询问的内容). ③First of all, what are ______(第一个问题)? ④Secondly, when will ______(第二个问题)? ⑤Thirdly, is _____