Thông thường, dịch mạch rây có pH khoảng bao nhiêu?
A.7,5 – 8,0.
B.8,0 – 8,5.
C.6,0 – 6,5.
D.7,0 – 7,5.

Mạch rây gồm những loại tế bào nào?
A.Quản bào và mạch ống.
B.Mạch ống và mạch rây.
C.Quản bào và tế bào kèm.
D.Ống rây và tế bào kèm.

Mạch gỗ gồm những loại tế bào nào?
A.Mạch rây và mạch ống.
B.Quản bào và mạch ống.
C.Tế bào kèm và mạch rây.
D.Quản bào và tế bào kèm.

Chất hữu cơ chiếm tỷ lệ lớn nhất trong thành phần nhựa luyện là:
A.Bazơ nitơ.
B.Tinh bột.
C.Glucose.
D.Saccharose.

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
Everybody in the house woke up when the burglar alarm ________.
A.went out
B.came about
C.rang off
D.went off

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.
Our country will grow more fruits and vegetables ______.
A.to exporting
B.to export
C.exporting
D.export

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.
While I was looking through my old albums the other day, I _______ this photograph of my parents’ wedding.
A.turned down
B.came across
C.made up
D.took after

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
George has come ______ a brilliant idea for losing weight.
A.out on
B.across to
C.up with
D.through for

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
The couple were so busy with their careers that they had no time for each other, that’s when they started to _______.
A.drift apart
B.drift out
C.drift away
D.drift off

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
People are advised to ____ smoking because of its harm to their health.
A.cut down
B.cut in
C.cut off
D.cut down on