A1. Raw silk before being processed into a rough thread. One meter of thread has a mass of approximately $0,13 \mathrm{mg}$. What is the mass of $1 \mathrm{~km}$ of thread?
(A) $0,0013 \mathrm{~g}$
(B) $0,013 \mathrm{~g}$
(C) $0,13 \mathrm{~g}$
(D) $1,3 \mathrm{~g}$
(E) $130 \mathrm{~g}$
A1. A 1 m wire has a mass of $0.13 \mathrm{mg}$ or $0.00013 \mathrm{~g}$, so 1 km of wire has 1000 times that mass, which is $0.13 \mathrm{~g}$.