SN4 ""

No	Pattern	Freq
1	[verb] been shown to [be]	176
2	have been shown to [be]	176
3	has been shown to [be]	100
4	[vb -s] been shown to [be]	100
5	[vb base] been shown to [be]	62
6	have been shown to [be]	62
7	[adv] been shown to [be]	40
8	[adv] been shown to [be]	37
9	[vb past] been shown to [be]	13
10	had been shown to [be]	13
11	previously been shown to [be]	8
12	previously been shown to [be]	8
13	also been shown to [be]	7
14	also been shown to [be]	7
15	recently been shown to [be]	5
16	recently been shown to [be]	5
17	been shown to [be] [adj]	102
18	been shown to [be] [adj]	96
19	been shown to [be] [adv]	54
20	been shown to [be] [adv]	51
21	been shown to [be] [art]	30
22	been shown to [be] [art]	30
23	been shown to [be] [verb]	24
24	been shown to [be] a	23
25	been shown to [be] [vb pp]	22
26	been shown to [be] a	18
27	been shown to [be] effective	14
28	been shown to [be] effective	14
29	been shown to [be] more	6
30	been shown to [be] more	6