endeavored 是还没有成功的努力么? 我的理解是:他作为r&d chemist, a process technologist, and a production manager一直很努力。 如果是“他正在努力成为an r&d chemist, a process technologist, and a production manager”的话, 应该是he has endeavored to be an r&d chemist, a process technologist, and a production manager查看更多