计算下列物质的相对分子质量。7Q9c0B0Y;x3Y9X7n:w;M3x
(1)氧气(O2)1S1V't(B-e:\2G*}+W5Y,q7Q9c0B0Y;x3Y9X7n:w;M3x
(2)二氧化硫(SO2)5K2p3G+P5t's(@7Q9c0B0Y;x3Y9X7n:w;M3x
(3)氢氧化钙[Ca(OH)2] 6\)E,G(U8f7Q9c0B0Y;x3Y9X7n:w;M3x
(4)硝酸(HNO3)1v8F,s*F(c+r3^;B7Q9c0B0Y;x3Y9X7n:w;M3x