The fridge doesn't work，Why not consider a new one？（ ）
| A． |
buy |
B． |
bought |
C． |
to buy |
D． |
buying |
Your dream will not come true you keep trying your best．（ ）
| A． |
when |
B． |
unless |
C． |
whether |
D． |
because |
It about eight minutes for the light to travel from the sun to the earth．（ ）
| A． |
pays |
B． |
costs |
C． |
spends |
D． |
takes |
We are happy to see our city is developing these years than before．（ ）
| A． |
quickly |
B． |
more quickly |
| C． |
very quickly |
D． |
the most quickly. |
Robots more heavy work for us in the future．（ ）
| A． |
will do |
B． |
did |
C． |
have done |
D． |
were doing |
It is duty to protect the environment．（ ）
| A． |
we |
B． |
us |
C． |
ours |
D． |
our |