nếu 10a+b chia hết cho 7 thì a-2b chia hết cho 7 với mọi lla,b thuộc N

$\rm{giúp mình nhé}$ 1. Vì sao không nên đựng các đồ ăn chua (có tính axit) bằng các vật dụng làm bằng nhôm? 2. Vì sao không đựng vôi sữa trong chậu nhôm?

A, 7√a^2 -a (a>0) B, √a-3^2-2a (a<1)

`( x - \frac{3}{2} )( x + 1 ) > 0`

E tăng điểm rồi ạ,mong mọi người giúp

Cho tam giác ABC vuông tại A.Kẻ đường cao AH,trung tuyến AM.Vẽ MD vuông góc AB;ME vuông góc AC(M thuộc BC;D thuộc AB;E thuộc AC) a)Gọi I là trung điểm DE.CM I thuộc trung trực của AH b) Tìm vị trí của M trên BC thì DE có độ dài bé nhất

76. What ___________________Mr. Ha (live)_______________? 77. Monkeys can (climb)_________________ the tree. 78. Hang (go)__________________to the bookshop now because she (want) ___________to buy some books. 79. We (go) ______________to market and (buy)_________________some fruits. 80. Now, Lan (study)________________English and Lien (listen)______________to music. 81. Everynight , she (have)____________________dinner at 7.00 p.m. 82. Every year, I usually (go)______________________Vietnam. 83. In the summer, I sometimes (go)____________________swimming. 84. Every everning, my mother (like)___________ watching television. 85. Lan (have)_______________breakfast and (go)___________to school at 6.30 a.m. 86. We (not read)___________________after lunch. 87. Tom (be)___________my friend. He (play)______________sports everyday. 88. ______________your students (play)__________soccer every afternoon? 89. He (go)_____________to bed at 11.30 p.m. 90. They (go)___________home and (have)___________lunch. 91. ___________he (play)__________sports? 92. He (teach)_______________English in a big school in town. 93. Everyday she (go)____________to work by bike. 94. We usually (read)_________books, (listen)_________to music or (watch)_______TV. 95. Sometimes, I (play)__________badminton. 96. Ann (like)____________her job very much. 97. ___________your mother (walk)_________to the market?

a/ Nêu đặc điểm phân biệt giữa lớp cá sụn và lớp cá xương. Cho ví dụ. b/ Để bảo vệ nguồn lợi của cá ta cần phải làm gì?

41. My sister (get)______________ dressed and (brush)_______________her teeth herself at 6.30 everyday. 42. Mrs. Smith (not live)____________in downtown. She (rent)___________in an appartment in the suburb. 43. How _________your children (go)_________________to school everyday? 44. It's 9 o'clock in the morning. Lien (be)________in her room. She (listen) _______________to music. 45. We_______________________(play) soccer in the yard now. 46. My father (go)___________ to work by bike. Sometimes he(walk)______________. 47. _________You (live)________near a market? _ It (be)____________noisy? 48. Now I (do)_____________the cooking while Hoa (listen)_______________to music. 49. At the moment, Nam and his friends (go)_______________________shopping at the mall. 50. In the autumn, I rarely (go)______________sailing and (go)__________to school. 51. I (write)_____________________________ a letter to my friend now. 52. At 12 a.m every day, I (have)______________lunch and (go)____________to bed. 53. On Monday, I (have)________________________ math and Art. 54. On Friday, I (have)______________________English. 55. At the moment, I (eat)______________an orange, and My sisters (Play)_______ Tennis. 56. _______her bag (be)? - No, they(not be)______________. 57. What time _____________your children (go)____________ to school? 58. He (live)________________in HCM City. 59. What time___________your brother usually (get)___________up? 60. My house (be)_________in the city and it (be)_________small. 61. Every morning , we (have)__________breakfast at 7.00 am. 62. This (be)________a book and there (be)_________pens. 63. Mr. Quang (live)____________in the countryside. He (have)__________a big garden. 64. John (not have)______________Literature lesson on Friday. 65. What time _________you (start)___________your class? 66. ___________you (be) in class 12A3? 67. Mrs. Ha (learn)__________________in Hanoi, but she (not live)__________________ there. 68. My brother (not live)____________________in London; he (live)_______________ in Manchester. 69. Now Mr. Long (design) ____________________his dream house. 70. He (like)_____________APPLES, but he (not like)_____________________bananas. 71. __________________she (like)______________apples? 72. Usually, I (have)_________________lunch at 12.00. -__________________you (have) ___________________lunch at 11.00? 73. He can (swim)_______________but I can't(swim)_____________________. 74. At the moment, my sister (read)___________________ a comic book. 75. I (like)__________________ice-cream.

giúp mình bài 5 này vs ạ cảm ơn trước