SN4 ""

No	Pattern	Freq
1	it have been [verb] that [adj]	299
2	it have been [vb pp] that [adj]	298
3	it has been [verb] that [adj]	263
4	it have been [verb] that [det]	152
5	it have been [verb] that [adj]	115
6	it have been suggested that [adj]	69
7	it have been suggest that [adj]	69
8	it have been [verb] that this	57
9	it have been [verb] that this	57
10	it have been argue that [adj]	36
11	it have been argued that [adj]	36
12	it have been estimated that [adj]	34
13	it have been estimate that [adj]	34
14	it have been [verb] that [num]	29
15	it had been [verb] that [adj]	28
16	it have been show that [adj]	27
17	it have been shown that [adj]	27
18	it have been [verb] that these	21
19	it have been [verb] that these	21
20	it have been [verb] that some	20
21	it have been [verb] that some	20
22	it have been [verb] that such	15
23	it have been [verb] that such	15
24	it have been find that [adj]	14
25	it have been found that [adj]	14
26	it have been claimed that [adj]	12
27	it have been claim that [adj]	12
28	it have been assumed that [adj]	11
29	it have been assume that [adj]	11
30	it have been [verb] that one	9