Giải phương trình \(\sin 3x.\left( {\cos x - 2\sin 3x} \right) + \cos 3x.\left( {1 + \sin x - 2\cos 3x} \right) = 0\).
A.\(\dfrac{\pi }{8} + \dfrac{{k\pi }}{2}\).
B.\(\dfrac{{k2\pi }}{3}\).
C.\(\dfrac{{k\pi }}{4}\).
D.Vô nghiệm.

Tên thay thế của CH3-CH=O là:
A.etanal.
B.etanol.
C.metanal.
D.metanol.

Mrs Ramsay was accustomed ______ in this rickety house.
A.by living
B.to living
C.with living
D.living

(6) ___________
A.ideas
B.principles
C.regulations
D.laws

Phân số tối giản là:
A.\(\frac{5}{7}\)     
B.\(\frac{6}{4}\)   
C.\(\frac{6}{9}\)               
D.\(\frac{4}{{12}}\)

Cho khối hộp chữ nhật có ba kích thước \(2\); \(3\); \(7\). Thể tích của khối hộp đã cho bằng
A.\(7\).
B.\(42\).
C.\(12\).
D.\(14\).

Nancy failed to understand what the story was about until she saw the film based on it.
A.Nancy doesn't understand what the story is about.
B.Not until she saw the film based on it did Nancy understand what the story was about.
C.It was until she saw the film based on it that Nancy understood what the story was about.
D.Nancy went to see the film before she read the story.

You never really know where you are with her as she just blows hot and cold.
A.keeps changing her mood
B.keeps taking things
C.keeps going
D.keeps testing

Một nguyên tử M có 30 electron và 35 nơtron. Kí hiệu nguyên tử M là
A.\({}_{35}^{65}M\).
B.\({}_{30}^{65}M\).
C.\({}_{35}^{30}M\).
D.\({}_{65}^{30}M\).

(7) ___________
A.catch
B.hold
C.include
D.embrace