In addition to the revenue, the Ministry for Human Resources and Social
Security estimated that esports would fill 2 million jobs over the next five
years, quadruple the size in 2019 of
500,000.
1.请问粗体部分在句中作什么语法成分?
2.quadruple在这里的词性是怎样的?如果是动词为什么不用现在分词作伴随呢?