5."fly-in":I may translate it to "遠道而來"
Chinese firms tended to learn more from multinationals that had taken the trouble to build their own large sales forces in China, he says.
中國企業通常從跨國公司學到的東西更多,而跨國公司則在建立他們自己的巨大銷售力量時困難重重
*** take the trouble是費心血的意思(make the effort)
forces means "any body of persons combined for joint action" here.
有些跨國公司努力在華建立他們自己的龐大銷售隊伍。中國企業往往能從這樣的公司學到更多的東西。