Hai đoạn thẳng AC,BD vuông góc với nhau tại trung điểm của mỗi đoạn thẳng. Tính các độ dài AB,BC,CD,DA biết AC= 12cm, BD=16cm.

For hundreds of years, giving flowers have been a social means of communication. In the United States , flowers are often given during rites(nghi thức) of passage, for commemorating special occasions(dịp) or as a heartfelt(chân thành) gift between loved ones and friends. Flower gifting also occurs(hầu hết) in most countries around the world. However, the meanings and traditions often vary(khác nhau).While students traditionally gave their favorite teacher an apple in past years , in China, teachers are given flowers. Peonies(hoa mẫu đơn) are b far the flower most often given in China. They are also quite popularly used for weddings . Strangely(một cách nghiêm túc), potted(chậu) plants are not considered a pleasant gift among Asian cultures. The people believe that like a plant confined by a pot, the gift symbolizes a binding(rành buộc) or restriction(hạn chế).In Russia, in lieu of giving birthday presents, the guest of honor receives a single flower or an unwrapped bouquet . Floral arrangements or baskets are not given. Russians celebrate a holiday known as Woman's Day. Traditional gifts include red roses, hyacinths or tulips. When there is a funeral or other occasion where someone wishes to express s ympath y,carnations, lilies or roses are given in circular configurations, which signify the transition of birth, life and death to rebirt h. In thi sinstance, the color of choice is commonly yellow. For joyos occasions , arrangements and bouquets generall y contain an odd number of flowers. In the times of ancient Rome, brides carried flowers to scare away evil spirits and encourage fertility. The Dutch believed that flowers were food for the soul. When invited to someone's white lilies, which are usuall y seen at funerals. Unlike the United States, red roses are a symbol of love. A. The fascinating tradition of giving flowers. B. The different meanings of flowers in different cultures. C. The comparison of giving flowers between Asian and European cultures. D. The kinds of flowers people often give each other in different cultures. Question 17: What does the word "They" in paragraph 2 re fer to? A. Students B. Teachers C. Flowers D. Peonies Question 18: Why should not you give a potted plant to an Asian? A. Because the Asian prefer to be given flowers. B. As this gift is often given at weddings in Asia. C. Since this gift is believed to sy mbolize an astriction and limitation in Asia. D. Because Asian students like to give an apple or flowers to others. Question 19: According to the passage, the following flowers are given at Woman's Day in Russia, EXCEPT . A. red roses B. hyainths C. tulips D. yellow roses Question 20: What could the word "fertility" in paragraph 4 best be replaced by ? A. fecundity B. good spirit C. happiness D. loyalty Question 21: The word "superstitions" in paragraph 4 is closest in meaning to A. deep-seated belief B. unfounded belief C. religious belief D. traditional belief Question 22: In which country should not people bring white lilies to other houses? A. China B. Russia C. Great Britain D. United States Question23: It can be inferred from the passage that A. People can give flowers to the American in any occasion. B. Egyptians are rather comfortable when receiving flowers at funerals and weddings. C. Flowers given in Britain are in even numbers in any case. D. At the funerals in any cultures, flowers are gifted in circular configurations.

Hãy kể tên một số loại hình kinh doanh và tên 5 loại thuế mà em biết

Viết các phương trình phản ứng xảy ra cho các sơ đồ sau: a) HCl  Cl 2  FeCl 3  NaCl  HCl  CuCl 2  AgCl b) KMnO 4 Cl 2 HCl FeCl 3 AgCl Cl 2 Br 2 I 2 ZnI 2 Zn(OH) 2 f) CaCl 2  NaCl  HCl  Cl 2  CaOCl 2  CaCO 3  CaCl 2  NaCl  NaClO

Giúp mình bài 2 và bài 3 với , hoặc giúp 1 bài cũng được , cảm ơn các bạnn

Giúp mk với, làm ơn,,,: Đặt 1 câu trần thuật đơn không có từ "là " có sử dụng 1 trong các biện pháp nghệ thuật sau : Nhân hóa , so sánh và từ láy

Câu 1: Hai văn bản Sông nước Cà Mau và Vượt thác đều miêu tả cảnh sông nước. Em hãy nêu những nét đặc sắc của phong cảnh thiên nhiên được miêu tả ở mỗi bài và nghệ thuật miêu tả của mỗi tác giả. Câu 2:

stress 6. A. American B. Canadian C. Australian D. Portuguese 7. A. monument B. symbolize C. attraction D. spectacle 8. A. natural B. trainee C. unique D. parade 9. A. territory B. festivity C. traditional D. geography 10. A. official B. legendary C. historic D. iconic

Chợ rau bán 3500đ/bó cải, 10000đ/3 bó cải. Hỏi mua 8 bó cải giá bao nhiêu?

Giúp mình giải hai bài này với!!!!!