cho biểu thức F= ( √x : 1 - 1 : √x ) . ( √x : √x + 1 + √x : √x - 1 ) vs x > 0, x khác 1 a) rút gọn F b) tìm x để F - 6 < 0

Nêu những biện pháp bảo vệ nơi sinh sống của động thực vật trên Trái Đất?

Vẽ giúp Linh cái nỳ với nek ! Tô hay hok tô đều được nha ! Mơn mn

Em có suy nghĩ gì về những thành tựu khoa học kỹ thuật của nước ta.

Làm hộ mình nhé. Mình cảm ơn nhìu ạ.

nêu khái niệm của nồng độ dung dịch và nồng độ mol

lấy vd về 2 loài động vật có xương sống và không có xương sống có lợi cho mùa màng , có hại cho mùa màng

1.Yesterday I met a friend that I___for ages. A.don't meet B. haven't seen C.didn't see D. hadn't seen 2. Laura needed a break because she ____ all morning. A. had studied B. studied C. has been studying D. had been studying 3. Lorraine _____ English for 12 years before she moved to England. A.learnt B. had learnt C.has learnt D. had been studying 4. I did not go out last night because I_____all day. A. had worked B. worked C. had been working D. both A and C 5.Orla left fit for the marathon because she ____ a lot A. trained B. was training C. had trained D.has trained 6. When I went to see Ms Winter , her secretary told me that she____on the phone for two hours. A. was speaking B. spoke C.had spoken D. had been speaking 7.You got sick because you ___ the whole time. A. had been eating B. had eaten C.have been eating D.ate 8. I didn't like my old neighbor . He ____ the drum all the day ! A. was always playing C.always played B. is always playing D.always was playing 9. The musician_____ in this town for ten years when he became directer of the opera house. A.lived B.was living C. had gone D.were going 10.We ____ out with each other for two years before I mis his family A. went B. had went C. had gone D.were going

Nêu đặc điểm khí hậu chung ở Bắc mỹ

`\frac{1}{2}`.`\frac{1}{2}`.`0,8-``3%`