Cho tam giác ABC vuông tại A đường cao AH có AB =12cm,AC=16cm.

1)Tính độ dài BC, AH

2)Tính số đo góc B, góc C

3)Từ H kẻ HI⊥AC (I∈AC). Chứng minh rằng AH. IH =HC. HB

Đâu là hình thức đấu tranh trọng tâm của phong trào cách mạng 1930-1931?

A. Vũ trang chính quy 

B. Chính trị quần chúng  

C. Vũ trang quần chúng 

D. Chính trị thương lượng

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

One of the most interesting authors of the twentieth century, J.R.R. Tolkien, achieved fame through his highly inventive trilogy, The Lord of the Rings. Born in 1892, Tolkien received his education from Oxford and then served in World War I. After the war, he became a professor of Anglo-Saxon and English language and literature at Oxford University.

Although published in 1965, the three books that comprise The Lord of the Rings were written in intervals from 1936 to 1949. This was mainly due to Tolkien’s responsibilities as a professor and the outbreak of World War II. By the late 1960s, this fascinating trilogy had become a sociological phenomenon as young people intently studied the mythology and legends created by Tolkien. The trilogy is remarkable not only for its highly developed account of historical fiction but also its success as a modern heroic epic. The main plot chronicles the struggle between good and evil kingdom as they try to acquire a magic ring that has the power to rule the world. The novels, which are set in a time called Middle Earth, describe a detailed fantasy world. Established before humans populated the Earth, Middle Earth was inhabited by good and evil creatures such as hobbits, dwarves, elves, monsters, wizards, and some humans. The characters and the setting of Middle Earth were modeled after mythological stories from Greece and Northern Europe. Although readers have scrutinized the texts for inner meaning and have tried to connect the trilogy with Tolkien’s real life experiences in England during World War II, he denies the connection. He claims that the story began in his years as an undergraduate student grew out of his desire to create mythology and legends about elves and their language. Tolkien was a masterful fantasy novelist who used his extensive knowledge of folklore to create a body or work that is still read and enjoyed throughout the world today.

What can we assume is true about Tolkien?

A. He enjoyed studying mythology and folklor

B. He spent most of his life in the military

C. He wrote the trilogy about his real life experiences

D. He lived in Greece

Read the passage and choose the best answer.

A pilot cannot fly by sight alone. In many conditions, such as flying at night and landing in dense fog, a pilot must use radar, an alternative way of navigating. Since human eyes are not very good at determining speeds of approaching objects, radar can show a pilot how fast nearby planes are moving. The basic principle of radar is exemplified by what happens when one shouts in a cave. The echo of the sounds against the walls helps a person determine the size of the cave. With radar, however, the waves are radio waves instead of sound waves. Radio waves travel at the speed of light, about 300,000 kilometers in one second. A radar set sends out a short burst of radio waves. Then it receives the echoes produced when the waves bounce off objects. By determining the time it takes for the echoes to return to the radar set, a trained technician can determine the distance between the radar set and other objects. The word “radar”, in fact, gets its name from the term “radio detection and ranging”. “Ranging” is the term for detection of the distance between an object and the radar set. Besides being of critical importance to pilots, radar is essential for air traffic control, tracking ships at sea, and for tracking weather systems and storms. 

 What might be inferred about radar?  

A. It takes the place of a radio. 

B. It has improved navigational safety. 

C. It was developed from a study of sound waves. 

D. It gave birth to the invention of the airplane.

Choose the word whose underlinedpart ispronounced differently from that of the others

A. coughed

B. ploughed

C. laughed

D. touched

Phát biểu nào sau đây đúng? 

A. Để rửa sạch ống nghiệm có dính anilin, có thể dùng dung dịch HC1 

B. Ở nhiệt độ thường, tất cả các amin đều tan nhiều trong nước

C. Các amin đều không độc, được sử dụng trong chế biến thực phẩm

D. Tất cả các amin đều làm quỳ tím ẩm chuyển màu xanh