英文文法構句問題

各位好
有個題目是:

Michael Phelps, as ____________, fulfilled his goal of winning eight gold medals inthe 2008 Olympics.

答案是: had been expected
我的問題是: 主詞是 Michael Phelps, 動詞是 fulfilled
as 的詞性為何?
had been expected 也是動詞,
as 是連接詞嗎? 反正構句我不太懂, 感覺句子變兩個動詞, 但沒conj.
6 answers 6