SN4 ""

No	Pattern	Freq
1	it difficult [to-vb]	1117
2	it difficult get	55
3	it difficult to get	53
4	it difficult to believe	35
5	it difficult to understand	35
6	it difficult understand	35
7	it difficult believe	35
8	it difficult accept	24
9	it difficult to see	24
10	it difficult see	24
11	it difficult to accept	24
12	it difficult cope	22
13	it difficult to cope	22
14	it difficult to make	20
15	it difficult make	20
16	it difficult to maintain	17
17	it difficult to keep	17
18	it difficult maintain	17
19	it difficult keep	17
20	it difficult to identify	15
21	it difficult identify	15
22	it difficult concentrate	14
23	it difficult to concentrate	14
24	it difficult to know	13
25	it difficult know	13
26	it difficult to take	12
27	it difficult take	12
28	it difficult to breathe	12
29	it difficult breathe	12
30	it difficult determine	11