UP TO NOW, WE ____________ THE POLLUTION PROBLEMS YET. A. HAVEN
13. Up to now, we ____________ the pollution problems yet.
a. haven?t solved
b. are not solving
c. hadn?t solved
d. will not have solved
13. Up to now, we ____________ the pollution problems yet.
a. haven?t solved
b. are not solving
c. hadn?t solved
d. will not have solved