Một chồng sách gồm 4 quyển sách Toán, 3 quyển sách Vật lý, 5 quyển sách Hóa học. Hỏi có bao nhiêu cách xếp các quyển sách trên thành một hàng ngang sao cho 4 quyển sách Toán đứng cạnh nhau, 3 quyển Vật lý đứng cạnh nhau?

(2/3×x-1/3)^5=1/243 Mn ơi lm ơn giúp mk nha.

Ah chị giúp em với ạ Em cảm ơn ah chị nhiều ạ

e cần gấp lắm ạ trb đầy đủ hứa vote 5s ạ

giải bài 33 giải hộ bạn mk nhờ mak đang bận mong mn làm hộ

làm mỗi bài 26 trước 2 giờ 45 phút chiều nay

Công cha như núi ngất trời Nghĩa mẹ như nước ở ngoài biển Đông Núi cao biển rộng mênh mông Cù lao chín chữ ghi lòng con ơi Câu hỏi Nêu cảm nghĩ của em về bài ca dao trên

Vì sao không được tưới cây vào lúc trưa nắng?

Read the following passage and choose the option (A, B, C or B) that best answers each of the questions below. One of the most obvious negative aspects of social networking is losing face- to-face contact with other people. Teens are sitting around with their phone in their hands all day long, tapping messages onto screens instead of communicating with real people. Many teenagers feel more comfortable with virtual friends than with real ones. The majority think that it is easier to chat on the Internet because they lack communication skills. It is also true that parents often have no knowledge about what their kids do with their phones or computer. Crosby says that, "While kids are plugged in to social media, only about 40% of parents are involved themselves." And because parents don't know the full picture, they also don't know how to deal with a teenager's potential overuse of social media and might not even be aware that a problem exists. Therefore, social networking can be much more immediately engaging with the teenager's life than parents are, and this fact makes virtual communication feels more "real" than face-to-face communication. (Source: Adapted from We have kids) 41. What is the main idea of the passage? A. Parents should use social networks more to understand their children. B. Students are using social networks too much. C. Social networking brings negative effects to student’s face-to-face communication. D. Virtual life is easier than real life. 42. What do most teenagers think about chatting on the Internet? A. Chatting on the Internet is easier than talking with real people. B. Chatting on the Internet is more difficult than talking with real people. C. Chatting on the Internet is funnier than talking with real people. D. Chatting on the Internet is more boring than talking with real people. 43. The percentage of 40% refers to A. The number of parents who let their children use social media. B. The number of parents who do not want their children to use media. C. The number of parents who use social media. D. The number of parents who do not use social media. 44.Which sentence is NOT TRUE according to the passage? A. The majority of teenagers find it easier to communicate with virtual friend B. The majority of teenagers lacks communication skill. C. The majority of parents know how to use social media with their children D. The majority of parents do not know how to deal with their children overuse of social media. 45. Which of the following best explains the word “overuse” in the passage? A. using something overnight B. using something too much C. using something without thinking D. using something with carelessness

Làm nhanh + đúng vote 5* + CTLHN ạ