Giữa hiệu điện thế 3V, người ta mắc song song hai điện trở R1=2 ôm, R2=3 ôm
a/ tính điện trở tương đương của đoạn mạch
b/ tính cường độ dòng điện trong mạch chính và trong các mạch rẽ

3. At last, we could draw the....( conclude/ conclusion/ conclusive/ conclusively)
4. .....( commerce/ commercial/ commercially) fishing has been carried out since the Middle ages
5. New films always get public....( react/ reaction/ reactivate) seriously
6. The scenery was beautiful beyond....( describe/ description/ descriptive/ descriptives)
8. The general...( impress/ impression/ impressive)
7. Wich....( character/ characterize/ characterless) distinguishes American English and British English
9. She always listens.....( attention/ attentive/ attentively) to what she is told
10. This car doesn't consume much petrol. It's....( economic/ econmics/ economy/ exonomical)
11. Hunters have caused the.....( lose/ loss/ lost/ loaing) of wild animals
12. Im spite of his...( tire/ tired/ titedness/ tiredly), he managed to finish the race
13. Try to avoid....( risappoint/ disappointing/ disappointed/ disappointment) other people
14. Our success came after some....( fail/ failing/ failures/ failure)
15. You need....( confide/ confidence/ confident) when having an interview
16. I have lives in this city for 6 years and i am...( experience/ experienced/ expirencing/ ezperiences) in traffic jams
17. Vietnam is an...( agriculture/ agricultural/ agriculturally) country
18. Water and air are more and more.....( contaminate/ comtaminating/ contaminated/ contamination)
19. They have no.....( intend/ intention/ intentional) of selling the house which they inherited from their mother
20. The environmental....( destroy/ destruction/ destrucrive/ destructively) is doing harm on us
21. When we burn garbage, we get...( pleased/ pleasure/ pleasant/ unpleasant) odors

1. The young usually do things....( enthusiasm/ enthusiastic/ enthusiast/ enthusiastically)
2. The industrial.....( develop/ development/ developing) has made many changes in our country