Personal computers ______ in 1976. It has changed the whole world.
#44711
A
have invented
B
were invented
C
is invented
D
invented
推荐题目
Sixteen-year-olds should _________their ears pierced.
#44743
A
be allowed to get
B
be allow to get
C
allow to get
D
be allowed getting
Trees ________ every year to make our city greener.
#44941
A
plant
B
are planted
C
were planted
D
will be planted
Paul doesn’t have to be made _______ . He always works hard.
#44866
A
to learn
B
learn
C
learning
D
learns