SN4 ""

No	Pattern	Freq
1	it has been [vb pp] [adj]	84
2	it have been [vb pp] [det]	79
3	it have been [vb pp] [adj]	63
4	it had been [vb pp] [adj]	59
5	it have been [vb pp] that	51
6	it have been [vb pp] that	51
7	it have been made [adj]	21
8	it 's been [vb pp] [adj]	21
9	it have been [vb pp] [num]	18
10	it have been [vb pp] several	12
11	it have been [vb pp] several	12
12	it have been suggested [adj]	10
13	it have been [vb pp] clear	9
14	it have been [vb pp] clear	9
15	it have been given [adj]	6
16	it have been shown [adj]	6
17	it have been reported [adj]	5
18	it have been [vb pp] open	5
19	it have been [vb pp] many	5
20	it have been estimated [adj]	5
21	it have been [vb pp] open	5
22	it have been observed [adj]	5
23	it have been [vb pp] many	5
24	it have been found [adj]	5