1. up to now, we...the pollution problems yet A.haven't solved B.hadn't solved C.are not solving D.will not have solved 2. he...very hard lately A.is working B.has been working C.will have been working D.was working 3. we...our classroom yet A.don't clean B.didn't clean C.haven't cleaned D.aren't cleaning 4. i...to getting up early when i was a student A.got used B.was used C.didn't use D.both A and B 5. you...late for school too many times. i'll talk to your parents about this A.were B.was C.has been D.have been 6. this time last week, i...to Dalat A.have driven B.drove C.was driving D.have been driving 7. whenever a problem..., we try to discuss and find solution as soon as possible A.comes by B.comes in C.comes off D.comes up 8. my father likes...stamps A.collecting B.collected C.collect D.collection 9. my...in the family is helping my younger brother with his study A.task B.activity C.job D.responsibility 10. our grandparents and parents often give us good....on important matters A.ideas B.advice C.examples D.thoughts