SN4 ""

No	Pattern	Freq
1	have become a [adj] [noun]	656
2	have become a [adj] [noun sg]	648
3	have become a [adj] [noun]	644
4	have become a [adj] [noun]	485
5	has become a [adj] [noun]	339
6	had become a [adj] [noun]	214
7	have become an [adj] [noun]	173
8	have become a [adj] [noun]	58
9	have become a [adj] part	45
10	have become a [adj] part	45
11	have become a major [noun]	40
12	have become a major [noun]	40
13	have become a important [noun]	26
14	have become a important [noun]	26
15	have become a [adj] feature	21
16	have become a [adj] feature	21
17	have become a [adj] issue	20
18	have become a [adj] issue	20
19	to have become a [adj] [noun]	18
20	have become a [adj] [noun]	18
21	have become a regular [noun]	15
22	have become a regular [noun]	15
23	have become a [adj] problem	13
24	have become a [adj] problem	13
25	have become a political [noun]	12
26	have become a political [noun]	12
27	have become a popular [noun]	10
28	have become a integral [noun]	10
29	have become a [adj] force	10
30	have become a national [noun]	10