A:﹣4
B:4
C:﹣16
D:16
They ____ (plant) trees from 7:00 to 9:00 last Sunday.
2.1×0.3=
0.5×0.8=
3÷0.5=
2.1÷0.3=
0.37÷0.1=
0.25×4=
3.6÷6=
4×0.23=
3÷2=
0.64÷0.8=