时间
4:00
5:00
6:00
7:00
8:00
9:00
10:00
电压/V
1.1
1.5
2.4
3.2
3.8
4.6
6.0
电流/A
0.60
0.68
0.80
0.88
0.92
0.96
1.00
—People near the lake didn't allow them to________ a factory so as not to pollute the water.
设集合A={1,2},则满足A∪B={1,2,3}的集合B的个数是( )