小李骑摩托车上山每小时行20千米，3小时到达山顶．下山只用2小时，求小李骑摩托车往返的平均速度．
直接写出得数．6÷= ×= 0÷= 4.1﹣÷=﹣= ÷= ×8×= 化简比0.6：=
直接写出得数．×= ×4= ×= ×= 3×=÷2= = ×= 12= ﹣1÷2=
直接写出得数．×= ÷= ÷26= = == ×÷= = = 1.2÷=
口算．×= ÷5= 1÷= 15×= 1.25×=×4= ÷= 1.8﹣40%= 12×（+）= ×6+4×=
直接写出复数． = = = == = = == = = =
= 
×
= 0÷
= 4.1﹣
÷
= 
÷
= 
×8×
= 化简比0.6：
=
×
= 
×4= 
×
×
= 3×
=
÷2= 
= 
×
= 12
= 
﹣1÷2=
×
= 
÷
÷26= 
= 
=
= 
×
÷
= 
= 
= 1.2÷
=
×
= 
÷5= 1÷
= 15×
= 1.25×
=
×4= 
÷
= 1.8﹣40%= 12×（
+
）= 
×6+4×
= 
= 
= 
=
= 
= 
= 
=
= 
= 
= 
=
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