解:设z=a+bi(a,b∈R),
而|z|=1+3i﹣z,即a2+b2-1-3i+a+
This is Bill. He's my friend. He's fat.
①糖类 ②蛋白质 ③脂肪 ④水分 ⑤维生素
⑥无机盐