SN4 ""

No	Pattern	Freq
1	at which [noun]	816
2	at [Wh det] [noun sg]	749
3	at what [noun]	339
4	at [Wh det] [noun pl]	286
5	at [Wh det] [noun prp]	205
6	at [Wh det] time	113
7	at [Wh det] time	111
8	at [Wh det] point	84
9	at [Wh det] point	84
10	at whatever [noun]	80
11	at [Wh det] level	52
12	at [Wh det] level	48
13	at [Wh det] stage	42
14	at [Wh det] stage	41
15	at [Wh det] price	36
16	at whose [noun]	35
17	at [Wh det] price	34
18	at [Wh det] [n mass]	30
19	at [Wh det] age	26
20	at [Wh det] age	25
21	at [Wh det] people	18
22	at [Wh det] people	18
23	at [Wh det] cost	18
24	at [Wh det] cost	18
25	at [Wh det] moment	15
26	at [Wh det] moment	15
27	at [Wh det] child	11
28	at [Wh det] women	11
29	at [Wh det] woman	11
30	at [Wh det] children	11