Nguyễn Đức Trung Kiên's Profile

Exercise 6: Put the verbs in brackets: Present perfect or present
perfect progressive. (1)
1. How long (you/ know) ......................................... Gerry?2. You look dirty. What (you/ do) ......................................... all day?3. How many times (Charles/ visit) ......................................... New York?4. She (learn) ......................................... French words for hours, but she still doesn’tremember all of them.5. The children (watch) ......................................... videos for two hours.6. (he/ study) ......................................... hard today?7. Sorry, I’m late, (you/ wait) ......................................... for long?8. We (not/ see) ......................................... Lisa recently.9. He (write) ......................................... his essay all day, but he hasn’t finished yet.10. How long (he/ wait) ......................................... for her?
 

(3x-2)(4x+5)=0

(4x+2)(x²+1)=0