计算:(-1)2+[20-(-2)3]÷(-4)
(-1)2+[20-(-2)3]÷(-4)
=1+[20-(-8)]÷(-4)
=1+28×(-14)
=1-7
=-6.
Labor is divided into how many stages
A. Two.B. Three.C. Four.D. Fiv
()叫地下水。