Có 2 lọ, một lọ đựng nước,một lọ đựng nước đường. a) Làm thí nghiệm đơn giản như thế nào thì có thể xác định đâu là nước tinh khiết ,đâu là nước đường ? b) từ nước đường, làm thí nghiệm đơn giản như thế nào để thu được 1 ít tinh khiết và một ít đường trong trạng thái rắn ?

câu 6,7,9 nha mọi người đang vội nên thông cảm :(

Giải phương trình ....................................

làm câu 9,10,11 nhanh ạ mình cần gấp

Exercise 10: Put the verbs in brackets in the PAST SIMPLE or the PAST CONTINUOUS tense. 1. He (sit) ______________ in a bar when I (see) ______________ him. 2. The light (go) ______________ out while I (have) ______________ tea. 3. While he (learn) ______________ to drive, he (have) ______________ an accident. 4. We (walk) ______________ to the station when it (begin) ______________ to rain. 5. He (have) ______________ a bad fall when he (repair) ______________ his roof. 6. It (start) ______________ to rain when we (play) ______________ football in the schoolyard yesterday. 7. The servant (drop) ______________ two cups while she (wash up) ______________ up last night. 8. While he (write) ______________ a letter, the telephone (ring) ______________.

Cho tam giác ABC bt MN//BC BM=3 AM=2 BC=6.5 tính Mn

Tìm GTNN của biểu thức ...............................

1. She told him, Could you shut the door, please? She ……………………………………………………………………………….. 2. He said, I am going home now. He said (that) …………………………………………………………………………….. 3. Sam asked her, Have you got 20 pounds? Sam asked her ………………………………………………………………………….. 4. He wanted to know, Which picture is the most famous one? He wanted to know ………………………………………………………………. 5. She said, I was biking yesterday. She said (that) ………………………………………………………………………. 6. He was told, Fill in the form! He was told …………………………………………………………………………… 7. She said, I am doing my homework. She said (that) ……………………………………………………………………… 8. They asked me, Did Paul lose the match? They asked me ………………………………………………………………….. 9. He told her, Dont call me before 7 o'clock! He ……………………………………………………………………………. 10. Mother said to me, I will buy that book for you. Mother said to me (that) ………………………………………………………………… 11. Cathy asked me, Is the movie interesting or boring? Cathy asked me ………………………………………………………………………………. 12. She said to him, I have invited you to my party. She said to him (that) …………………………………………………………………………. 13. They wanted to know, When is your birthday? They wanted to know …………………………………………………………………………….. 14. Susan said, I like classical music. Susan said (that) …………………………………………………………………………………….. 15. She asked me, Where did you meet her? She asked me ……………………………………………………………………………………………

(Chọn đáp án khác với các đáp án còn lại.)

cho hình chóp tam giác đều có cạnh bên bằng 2a và cạnh bên tạo với mặt đáy góc 45 độ. tính thể tích