?人们发现
...人们发现 it be discovered that ;it be found that ;it can be discovered that ;it can be found that ;it may be discovered that ;it may be found that ;it must be discovered that ;it must be found that ;it should be discovered that ;it should be found that 人们希望 it be hoped that ;it can be hoped that ;it may be hoped that ;it must be hoped that ;...