Xét hai mệnh đề chứa biến P(n): “ 3 n   <   n   +   100 ” và Q(n): " 2 n   >   n " với n   ∈   N * .

a) Với n = 1, 2, 3, 4, 5 thì P(n), Q(n) đúng hay sai?

b) Với mọi n ∈ N* thì P(n), Q(n) đúng hay sai?

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

Helen has never met such good person who is ready to help others

A. has

B. such good

C. who

D. to help

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 following questions.

A number of factors related to the voice reveal the personality of the speaker. The first is the broad area of communication, which includes imparting information by use of language, communicating with a group or an individual and specialized communication through performance. A person conveys thoughts and ideas through choice of words, by a tone of voice that is pleasant or unpleasant, gentle or harsh, by the rhythm that is inherent within the language itself, and by speech rhythms that are flowing and regular or uneven and hesitant, and finally, by the pitch and melody of the utterance. When speaking before a group, a person's tone may indicate uncertainty or fright, confidence or calm. At interpersonal levels, the tone may reflect ideas and feelings over and above the words chosen, or may belie them. Here the participant’s tone can consciously or unconsciously reflect intuitive sympathy or antipathy, lack of concern or interest, fatigue, anxiety, enthusiasm or excitement, all of which are.usually discernible by the acute listener. Public performance is a manner of communication that is highly specialized with its own techniques for obtaining effects by voice and /or gesture. The motivation derived from the text, and in the case of singing, the music, in combination with the performer's skills, personality, and ability to create empathy will determine the success of artistic, political, or pedagogic communication.

Second, the voice gives psychological clues to a person's self-image, perception of others, and emotional health. Self-image can be indicated by a tone of voice that is confident, pretentious, shy, aggressive, outgoing, or exuberant, to name only a few personality traits. Also the sound may give a clue to the facade or mask of that person, for example, a shy person hiding behind an overconfident front. How a speaker perceives the listener's receptiveness, interest, or sympathy in any given conversation can drastically alter the tone of presentation, by encouraging or discouraging the speaker. Emotional health is evidenced in the voice by free and melodic sounds of the happy, by constricted and harsh sound of the angry, and by dull and lethargic qualities of the depressed.

The word "Here" in line 9 refers to……………

A. At interpersonal levels

B. the tone 

C. ideas and feelings

D. words chosen 

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 following questions.

      Although speech is the most advanced form of communication, there are many ways of communicating without using speech. Signals, signs, symbols, and gestures may be found in every known culture. The basic function of signal is to impinge upon the environment in such a way that it attracts attention, as. For example, the dots and dashes of a telegraph circuit. Coded to refer to speech, the potential for communication is very great. Less adaptable to the codiíication of words, signs also contain meaning in and of themselves. A stop sign or a barber pole conveys meaning quickly and conveniently. Symbols are more difficult to describe than either signals or signs because of their intricate relationship with the receiver’s cultural perceptions. In some cultures, applauding in a theater provides performers with an auditory symbol of approval. Gestures such as waving and handshaking also communicate certain cultural messages.

          Although signals, signs, symbols, and gestures are very useful, they do have a major disadvantage. They usually do not allow ideas to be shared without the sender being directly adjacent to the receiver. As a result, means of communication intended to be used for long distances and extended periods are based upon speech. Radio, television, and the telephone are only a few.

The phrase “ impinge upon” in paragraph 1 is closest in meaning to________.

A. prohibit

B. intrude   

C. vary       

D. improve

Bằng cách sử dụng hằng đẳng thức a2 - b2 = (a - b)(a + b) hãy xét dấu f(x) = x4 - x2 + 6x - 9 và  g x   =   x 2   -   2 x   -   4 x 2   -   2 x