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 from 38 to 42.

HISTORY OF THE HELICOPTER

Although first flight generally attributed to a fixed-wing aircraft, the helicopter actually represents the first style of flight envisioned by humans. The ancient Chinese developed a toy that rose upward when spun rapidly. As early as the mid-sixteenth century, the great Italian inventor Leonardo da Vinci had drawn a prototype for the machine that we now know as the helicopter.

Early in the twentieth century, a great deal of experimentation and revision was taking place with regard to helicopter flight. The well-known phrase “two steps forward and one step back” provided an apt descriptor for early flight development. Uneven lift, known as dissymmetry, caused the early helicopters to flip over and confounded the inventors until the creation of the swash-plate; this allowed the rotor blade angles to be changed so that lift would be equal on each side of the shaft.

On November 13, 1907, the French pioneer Paul Cornu made history by lifting a twin-rotor helicopter into the air for a few seconds without ground assistance. Several models followed without significance until in 1924 when another French pioneer, Etienne Oehmichen, became the first to fly a helicopter for one kilometer. It was a historic flight of 7 minutes and 40 seconds. By 1936, solutions have been found to many of the problems with helicopter flight.

With the introduction of the German Focke-Wulf Fw 61, the first practical helicopter became a reality.

What is the topic of the passage?

A. Which aircraft was the first to fly. 

B. Aircraft design in the 20th century.

C. The development of the helicopter. 

D. The invention of the swash plate.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 33 to 37.

ENGLISH SPEELING

Why does English spelling have a reputation for being difficult? English was first written down when Christian monks came to England in Anglo-Saxon (33) ______. They used the 23 letters of Latin to write down the sounds of Anglo-Saxon speech as they heard it. However, English has a (34) _____ range of basic sounds (over 40) than Latin. The alphabet was too small, and so combinations of letters were needed to express the different sounds. Inevitably, there were inconsistencies in the way that letters were combined.

With the Norman invasion of England, the English language was put at risk. English survived, but the spelling of many English words changed to follow French (35) _____, and many French words were introduced into the language. The result was more irregularity.

When the printing press was invented in the fifteenth century, many early printers of English texts spoke other first languages. They made little effort to respect English spelling. Although one of the shortterm (36) _____ of printing was to produce a number of variant spellings, in the long term it created fixed spellings. People became used to seeing words spelt in the same way. Rules were drawn up, and dictionaries were put together which printers and writers could refer to. However, spoken English was not fixed and continued to change slowly - just as it still does now. Letters that were sounded in the Anglo- Saxon period, like the 'k' in 'knife', now became (37) _____. Also, the pronunciation of vowels then had little in common with how they sound now, but the way they are spelt hasn't changed. No wonder, then, that it is often difficult to see the link between sound and spelling.

Điền vào ô 37.

A. silen

B. dumb

C. quite 

D. speechless