plan was to go down a ladder at the boat and drop into about 15 feet of water. Everything went __2__ (perfect). His instructor Polly led him to the nearby reef. While __3__ (explore) the reef in 27 feet of water, Michael suddenly signaled a problem with his mask. Polly signaled back for him to clear it. He cleared it __4__ then later signaled the problem again. His mask was completely flooded with water. Michael made a sign __5__ he wanted to go up. Polly signaled, “No! Stay with me！”
According to Polly, even though scuba __6__ (train) teaches new divers how to deal with flooded masks, many beginners panic the first time water fills their masks during an actual dive. Michael wasn't like many beginners, though. He didn't panic. He did __7__ (exact) what he learned to do during his years. He stayed calm, __8__ (think) it through, and followed Polly's __9__ (instruct). Polly gradually led Michael to an area with shallower water. The group swam together back to the shore for a celebration of Michael's __10__ (amaze) accomplishment.
【文章大意】Michael 是一名潜水员。最值得一提的就是他第一次潜水的时候突遇意外，其他人可能已经惊慌失措，可是他却与众不同。
解析：
1．however考查上下文语境。根据第一段中的he was an extraordinary swimmer 可知他是一名非常优秀的潜水员，结合下文可知这里表示“但是他的第一次潜水却永生难忘”，是转折关系，而且本空缺少的是副词，能这样使用的是however。
2．perfectly考查词形转换。本空缺少的是副词，修饰谓语动词went。
3．exploring考查状语从句的省略。当主句和从句的主语一致，而且从句中含有be 动词的时候，从句中的主语和be 动词可以省略。从句中explore 的逻辑主语是Michael，动作是主动发出的，所以用exploring。
4．but考查连词。前后是转折关系，这里需要一个表示转折关系的并列连词。
5．that考查同位语从句。句中的he wanted to go up 解释名词sign，所以这是一个同位语从句。
6．training考查词形转换。这里指的是Michael 接受的要成为一名潜水员所必需的“训练”，所以用名词training 作主语。
7．exactly考查词形转换。这里用exactly 修饰动词do。
8．thought考查动词的时态。本句中含有三个连续的过去的动作，所以应该使用think 的过去式。
9．instructions考查词形转换。本空需要一个名词与follow构成动宾短语；而instruction意为“指示”时是一个可数名词，因此须用其复数形式。
10．amazing考查词形转换。Michael临危不惧，取得了令人惊讶的成就。这里用amazing修饰accomplishment。