自己做的英文文法解析,請指正是否有誤

Question

what makes this even more exciting is that when wildlife numbers start to rebound, all of a sudden there are new economic opportunities that present themselves.

1.what makes this even more exciting-為此句的主詞,what為代名詞

2.''that''後面一整句為名詞子句,做主詞補語用

3.when wildlife numbers start to rebound-為此名詞子句中的副詞子句

4.all of a sudden there are new economic opportunities that present themselves-為此名詞子句的主要子句,''all of a sudden''是介係詞片語做副詞用

Answer 1

what makes this even more exciting is that when wildlife numbers start to rebound, all of a sudden there are new economic opportunities that present themselves.

1.what makes this even more exciting-為此句的主詞,what為代名詞

2.''that''後面一整句為名詞子句,做主詞補語用

3.when wildlife numbers start to rebound-為此名詞子句中的副詞子句

4.all of a sudden there are new economic opportunities that present themselves-為此名詞子句的主要子句,''all of a sudden''是介係詞片語做副詞用
你所分析的都正確， 只有最後一句 all of a sudden 為一副詞片語作副詞用