电缆中ZQ<sub>21</sub>-3x50-250的3x50表示()。
A、3芯50mm
B、3芯50mm°
C、3芯50cm
A、3芯50mm
B、3芯50mm°
C、3芯50cm
A、YJV<sub>20sub>-3×240 B、YJV<sub>22sub>-3×240 C、VV<sub>22sub>-3×240 D、VV<sub>20sub>-3×240
A、(CH<sub>3sub>)<sub>3sub>N B、(CH<sub>3sub>)<sub>3sub>CNH<sub>2sub> C、CH<sub>3sub>NHCH<sub>2sub>CH<sub>3sub> D、CH<sub>3sub>CH<sub>2sub>NH<sub>2sub>
A、CH<sub>3sub>-NH-CH<sub>2sub>CH<sub>3sub> B、(CH<sub>3sub>)<sub>3sub>N C、(CH<sub>3sub>)<sub>3sub>CNH<sub>2sub> D、CH<sub>3sub>NHC<sub>6sub>H
A、(CH<sub>3sub>)<sub>3sub>CCH<sub>2sub>Br B、CH<sub>3sub>CH(CH<sub>3sub>)CH(CH<sub>3sub>)CH<sub>2sub>Cl C、CH<sub>3sub>CH<sub>2sub>CH(Br)CH<sub>3sub> D、CH<sub>3sub>CH<sub>2sub>CH(CH<sub>3sub>)CH<sub>2sub>(Cl)
A、SiO<sub>2sub>;Al<sub>2sub>O<sub>3sub>、Fe<sub>2sub>O<sub>3sub> B、Al<sub>2sub>O<sub>3sub>;Fe<sub>2sub>O<sub>3sub>、SiO<sub>2sub> C、Fe<sub>2sub>O<sub>3sub>;SiO<sub>2sub>、Al<sub>2sub>O<sub>3sub>
A、CH<sub>3sub>CH=CH<sub>2sub> B、CH<sub>3sub>CH=C(CH<sub>3sub>)<sub>2sub> C、(C<sub>2sub>H<sub>5sub>)<sub>2sub>C=C(CH<sub>3sub>)<sub>2sub> D、CH<sub>3sub>CH=CHCH<sub>3sub>
A、CH<sub>3sub>NH<sub>2sub> B、CH<sub>3sub>CH<sub>2sub>NHCH<sub>3sub> C、CH<sub>3sub>CH<sub>2sub>NH<sub>2sub> D、(CH<sub>3sub>CH<sub>2sub>)<sub>3sub>N
A、(CH<sub>3sub>CH<sub>2sub>)<sub>3sub>N B、C<sub>6sub>H<sub>5sub>NHCH<sub>3sub> C、(CH<sub>3sub>CH<sub>2sub>)<sub>2sub>NH D、CH<sub>3sub>NH<sub>2sub>