Robots have ______ humans from heavy work and offer us much more free time.A．freedB．be fre

We learn from the last paragraph that the author believes that ______.A．human culture cann

We ______ trouble from people who like leaving things around.A．used to haveB．have always h

_________（50）A.Humans have no direct perception o

_________（47）A.Humans have no direct perception o

_________（48）A.Humans have no direct perception o

_________（49）A.Humans have no direct perception o