The research requires more money than has been put in.这里为甚麽要用"has been put in"?

The research scientists often meet with problems( )a new type of instrument for their solution.备选：requireing / to require 选哪个呀?谢谢! 帮个忙,Sectors such as infrastructure,education,health and research require more careful consideration and often result in a more mixed picture.In all countries,the government retains an important role,in both the overall regulation of sectors and ‘the research isnt there patchwork we require the patchwork fabric the research on computer 还是 the research into computer? do the research on对吗 do the research on对吗 research Research research in the egypt,what occasions require special clothing? Does masturbation require an ejaculation to end the process? 请问这句话有错吗 The item you require is available from stock.require 不用d吗 不加的话岂不是有两个动词 require is THE PRACTICE OF SOCIAL RESEARCH怎么样 how to write the research proposal? journal of the operational research society怎么样 I did all of my research on the Internet对 all of my research 提问 require MUDDER_MODULE