select all that apply
choices:
a) 5
b) 7
c) 9
d) 4
e) 8
f) 10

Which of the following would be a reasonable estimate for the weight of a pencil? a. 1 × 10^-20 lb b. 1 × 10^20 lb c. 1 × 10^2 lb d. 1 × 10^-2 lb