Tính chất hóa học oxit,axit, bazơ Cảmơn

1. She _________ (live) in Japan since 1995.

A. live B.has lived C.have lived D.lives

2He started working as a teacher 6 months ago. A.He has worked as a teacher 6 months ago. B.He has working as a teacher 6 months ago. C.He has worked as a teacher for 6 months D.He has started working as a teacher 6 months ago.

3My teacher ________ us for 2 days. A. hasn’t teach B. hasn’t taught C. have teach D. haven’t taught

4. Tìm và sửa lỗi sai trong câu sau: Jinho have lost his key. He can’t find it anywhere. A.can't B.anywhere C.have D.his

5. He (be)…………. at his computer for seven hours. A.has been B.is C.was D.have been

6. I _______ a flight to Korea for 5 weeks. A. book B. have booked C. has booked D. books

7. Truong ___________ (perform) the same play since 2017 A.have performed B.performed C.has performed D.performs

8. Jun _______ France for 4 months. A. have learnt B. learnt C. learns D. has learnt 9. I’d better have a shower. I (not/have)………. one since Thursday. A.has not had B.had C.have not had D.didn't have

10. Key _________ (send) me an e-mail for 3 weeks. A.have sent B.has sent C.sends D.sent

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Tổng số hạt cơ bản trong nguyên tử X là 52, trong đó tổng số hạt mang điện nhiều hơn số hạt không mang điện là 16. Nguyên tử khối của X là

Số nhóm A trong bảng tuần hoàn là