Trong các hợp chất, lưu huỳnh, selen, telu có các số oxi hóa là
A.-2; +2; +4.
B.-2; +3; +4.
C.-2; +4; +6.
D.+2; +4; +6.

Tìm một số tự nhiên có hai chữ số biết rằng khi thêm số 4 vào bên trái số đó thì ta được số mới gấp 17 lần số đó.
A.22
B.56
C.47
D.25

A.nature
B.marriage
C.value
D.belief

When he came to the counter of pay, he found that he had _____ cash ____ his credit card with him.
A.either/or
B.neither/nor
C.both/and
D.not/neither

Stephanie was the last person to hand in the essay on the advantages and disadvantages of social networks.
A.The last thing Stephanie handed in was her essay on the advantages and disadvantages of social networks.
B.Everyone had submitted the essay on the advantages and disadvantages of social networks before Stephanie did.
C.Among the last people who submitted the essay on the advantages and disadvantages of social networks was Stephanie.
D.Everyone had heard about the essay on the advantages and disadvantages of social networks before Stephanie did.

Hợp chất X có công thức cấu tạo: CH3CH2COOCH3. Tên gọi của X là:
A.propyl axetat.
B.metyl propionat.
C.etyl axetat.
D.metyl axetat.

Which of the following statements best describes the dual vocational training programmes?
A.These programmes provide you with both theoretical knowledge and practical working experience.
B.These programmes require you to have only practical working time at a certain company
C.These programmes offer you some necessary technical skills to do your future job.
D.These programmes consist of an intensive theoretical course of two and a half years at a vocational school.

What is the main food of pandas?
 
A.Young bamboo trees
B.Bamboo roots
C.Bamboo trees
D.Bamboo leaves

Cho các tập hợp: \(C = \left\{ {x \in \mathbb{R}|\,\left| {2x - 4} \right| < 10} \right\}\), \(D = \left\{ {x \in \mathbb{R}|\,8 < \left| { - 3x + 5} \right|} \right\}\) và \(E = \left[ { - 2;5} \right]\)
Xác định tập hợp \(\left( {C \cap D} \right) \cup E\).
A.\(\left( {C \cap D} \right) \cup E = \left[ { - 3;\,\,7} \right]\)
B.\(\left( {C \cap D} \right) \cup E = \left( { - 2;\,\, - 1} \right) \cup \left( {\dfrac{{13}}{3};\,\,5} \right)\)     
C.\(\left( {C \cap D} \right) \cup E = \left( { - 3;\,\,7} \right)\)
D.\(\left( {C \cap D} \right) \cup E = \left[ { - 2;\,\,5} \right]\)

Young college and university students participate in helping the poor who have suffered badly in wars or natural disasters.
A.get involved in
B.interfere with
C.join hands
D.come into