Determine the number of significant figures in each of the following measurements:
(a) $4867 \mathrm{mi}$, (b) $56 \mathrm{~mL}$, (c) 60,104 tons,
(d) $2900 \mathrm{~g}$,
(e) $40.2 \mathrm{~g} / \mathrm{cm}^{3}$, (f) $0.0000003 \mathrm{~cm},(\mathrm{~g}) 0.7 \mathrm{~min}$,
(h) 46 amu.