một mảnh đất hình chữ nhật có chiều dài 34m và chiều rộng 15m.Người ta dành 25 % diện tích mảnh đất để làm nhà . tính diện tích phần đất làm nhà?

de ma 68 do

violympic chứ j

"C" nha bạn 

đúng 100% đó nha

Cho phản ứng hạt nhân: X + 9 19 F → 2 4 He + 8 16 O . Hạt X là

A. anpha.

B. nơtron.

B. nơtron.

D. prôtôn.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

Ever since humans have inhabited the earth, they have made use of various forms of communication. Generally, this expression of thoughts and feelings has been in the form of oral speech. When there is a language barrier, communication is accomplished through sign language in which motions stand for letters, words and ideas. Tourists, the deaf, and the mute have no resort to this form of expression. Many of these symbols of the whole words are very picturesque and exact and can be used internationally: spelling, however, cannot. Body language transmits ideas or thoughts by certain actions, either intentionally or unintentionally. A wink can be a way of flirting or indicating that the party is only joking. A nod signifies approval, while shaking the head indicates a negative reaction.  Other forms of nonlinguistic language can be found in Braille (a system of raised dots read with fingertips), signal flags, Morse code, and smoke signals. Road maps and picture signs also guide, warn and instruct people.

While verbalization is the most common form of language, other systems and techniques also express human thoughts and feelings.

What is the best title for the passage?

A. The Important of Sign Language

B. The Many Forms of Communication 

C. Ways of Expressing Feelings

D. Picturesque Symbols of Communication