Cho hai hàm số y = a x   v à   y = log a x  với a > 0 ; a ≠ 1 . Khẳng định nào sau đây sai?

A. Hàm số  y = log a x có tập xác định D = ( 0 ; + ∞ ) . 

B. Đồ thị hàm số  y = a x  nhận trục hoành làm đường tiệm cận ngang. 

C. Hàm số  y = a x và y = log a x đồng biến trên mỗi tập xác định tương ứng của nó khi a > 1.

D. Đồ thị hàm số  y = log a x nằm phía trên trục hoành.

Trong không gian với hệ tọa độ Oxyz, cho 3 điểm  A a ; 0 ; 0 ,  B 1 ; b ; 0 , C 1 ; 0 ; c  với a,b,c là các số thực thay đổi sao cho  H 3 ; 2 ; 1  là trực tâm của tam giác ABC. Tính  A - 1 ; - 1 ; 1

A.  S = 2

B.  S = 19

C.  S = 11

D.  S = 9

Mark the letter A, B, C, or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.

Our top priority is to clean and protect the environment in our neighbourhood.

A. hobby

B. job

C. preference

D. idea

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 23 to 27.

Every year, thousands of people travel to Britain in order to improve their standard of English. For many, however, this can be a painful experience due to the fact that it involves (23) _______ a strange school, staying in sometimes unpleasant accommodation and living in an unfamiliar culture. One answer to these (24) _______ is the Homestay method. With this, students are each assigned a teacher suited to their language requirements and interests. As well as giving individual tuition, the teacher provides the student (25 ) _______ information about what activities are available locally and takes them on trips. Students get between ten and twenty hours of tuition a week and are also expected to join in the family’s daily activities. The students speak English at all times and therefore learn (26) _______ to use the language in everyday situations. Homestay programmes usually last for up to four weeks. (27) _______ costs are higher than of regular language schools, students can feel confident that they will be receiving top-class language teaching in a safe and pleasant environment.

Question 23

A. studying

B. attending

C. going

D. learning