Chọn phát biểu sai. * 1 điểm A. Nguyên tử là hạt chất nhỏ nhất. B. Phân tử là một nhóm các nguyên tử kết hợp lại. C. Các chất được cấu tạo từ các hạt nhỏ riêng biệt gọi là các nguyên tử, phân tử. D. Giữa các nguyên tử, phân tử không có khoảng cách.

Giúp mình bài này với ạ, mình cảm ơn

1,rút gọn biểu thức sau:3 căn 2 - 2 căn 3 trên căn 2-căn 3

Độ dài đường chéo nhỏ là gì vậy ạ??

Bức xạ nhiệt là: * 1 điểm A. Sự truyền nhiệt bằng các tia nhiệt đi theo đường gấp khúc. B. Sự truyền nhiệt bằng các tia nhiệt đi thẳng. C. Sự truyền nhiệt qua chất rắn. D. Sự truyền nhiệt qua không khí.

JAZZ By Katie Atkins, aged 14 I play the trumpet in my school jazz band. Last month we held a jazz competition with bands from local high schools – and our band won! Each band had their own costumes, ranging from black school uniforms like my band wore, to brightly-coloured T-shirts. We didn’t look much like adult professional bands, but all of us were used to performing in competitions, so the quality of playing was amazing, especially considering everyone was so young. Players from each band even created new tunes right there on stage. It was exciting to watch – but even better when my band played on stage! We have a great jazz band at my school, but not everyone who wants to play in it gets accepted – only about half, in fact. But anyone who’s keen to play goes to jazz practice before school, and we often spend time together after school, listening to jazz and learning its language. There are also trips to jazz summer camps across the country – I’ve been to a couple and learnt a lot. Adults are often surprised that young people are getting interested in jazz. My music teacher thinks it’s because pop music isn’t challenging enough for people like me who are serious about music. But I find it exciting because it’s both new and old at the same time – you can create your own music, but you also feel you’re part of its history, as you’re playing on stage in the same way as great jazz performers before you. My school’s really lucky because we have great teachers, and parents who’ve supported us all the way. Without them, we’d never get anywhere with our music! 1. What is Katie trying to do in the text? A encourage young people to try to listen to more jazz B explain how jazz is becoming popular with young people C advertise young people’s jazz events in her area D give advice on how to create great jazz music 2. Katie says the bands in her school’s jazz competition A played music they’d written themselves before they came. B had little experience of playing in public. C played at a high level despite their age. D were dressed to look like professional jazz bands. 3. Most people at Katie’s school who are interested in jazz A attend early jazz sessions at school. B join the school jazz band. C learn about jazz in after-school classes. D go to jazz summer camps at the school. 4. Why does Katie enjoy playing jazz so much? A She finds it easier to learn than other forms of music. B She thinks it is more serious than pop music. C She likes the chance to perform with others on stage. D She feels in touch with jazz players of the past. 5. Which of the following would Katie write to a friend? A The competition was great, but I think I preferred being in the audience to playing – I was nervous! B My mum and dad always do all they can to help with my trumpet playing – I couldn’t do this successfully without their help. C One band wore really colourful clothes, but we chose dark costumes. Maybe that’s one reason why they won instead of us. D One music teacher left a while ago and no one’s replaced him yet. We just haven’t got anyone good to help us now.

*Nêu cách dùng của các "Đại Từ Quan Hệ": ( Who, whom, which, that, whose )

Đổ 5 lít nước ở 20°C vào 3 lít nước ở 45°C. Nhiệt độ khi xảy ra cân bằng nhiệt là: * 1 điểm A. 29,4°C B. 29,86°C C. 293,75°C D. 2,94°C

Giúp mình với, mình cần gấpp lắm ạ

Bản chất của sự dẫn nhiệt là gì? * 1 điểm A. Là sự thay đổi nhiệt độ. B. Là sự truyền động năng của các hạt vật chất khi chúng va chạm vào nhau. C. Là sự thay đổi thế năng. D. Là sự thực hiện công.