It is time that that可以省略吗

It is time that that可以省略吗 'it is believed that +从句' 中that可以省略吗? it is said that 可以省略that吗 句型It is said that 中的that可以省略吗 it is the first time that 是状语从句还是定语从句,that可省略吗? It is certain that he will win the match.这句话中的that可以省略吗 it is said that这that可省略吗? it is no doubt that的that可省略吗 It is high time that sb.should do sth.中的should可省略吗 It is known to all that he is a good student.这里的that可以省略吗? it is important that sb should do 中的should 可以省略吗? 强调句里的It is……that 可以省略吗?