SN4 ""

No	Pattern	Freq
1	[noun pl] who have been [verb] to	51
2	[noun pl] who have been [vb pp] to	48
3	[noun] who have been exposed to	8
4	[noun pl] [pron] have been exposed to	7
5	[noun pl] who have been exposed [prep]	7
6	[noun pl] who have been exposed [prep]	7
7	[noun pl] who have [be] exposed to	6
8	[noun pl] who have been exposed to	6
9	[noun pl] who have be exposed to	6
10	[noun pl] who have been expose to	6
11	[noun pl] who [verb] been exposed to	6
12	[noun pl] who have [been] exposed to	6