44×（400×90％）＝1584015840÷40＝396人396÷400＝99％应选A44×90％-40×90％＝1/10应选C1÷400÷44＝1/176001/17600×（1+20％）＝3/440001÷3/44000＝14666又2/314666又2/3÷40＝366又2/3366又2/3÷400约＝90％应选B
1.c2.b3.a4.b5.d
