A+B=20,B+C=16,C+A=18,则A+B+C=______.
根据题意得:2(A+B+C)=20+16+18=54,
所以:A+B+C=54÷2=27.
故答案为:27.
外科急腹症病人一般采取平卧或病人感觉最舒适的体位。
We ________ certain living things as birds not because they have long legs or short legs, but because they all have feathers.[ ]
A. suppose
B. classify
C. look
D. insist