Chọn câu đúng
A. $ ({{x}^{2}}-1)({{x}^{2}}+2x)={{x}^{4}}-{{x}^{2}}-2x $ .
B. $ ({{x}^{2}}-1)({{x}^{2}}+2x)={{x}^{4}}+2{{x}^{3}}-2x $ .
C. $ ({{x}^{2}}-1)({{x}^{2}}+2x)={{x}^{4}}-{{x}^{3}}-2x $ .
D. $ ({{x}^{2}}-1)({{x}^{2}}+2x)={{x}^{4}}+2{{x}^{3}}-{{x}^{2}}-2x $ .

Giá trị x thỏa mãn \[0,6x\left( {x - 0,5} \right) - 0,3x\left( {2x + 1,3} \right) = 0,138\] là
A.$ x=1,2 $.
B.$ x=3,6 $.
C.$ x=-0,4 $.
D.$ x=-0,2 $.

Tích $ 6{{x}^{4}}{{y}^{2}}:{{\left( \dfrac{1}{2}{{x}^{2}}y \right)}^{2}} $ bằng
A. $ 24{{x}^{2}}y $ .
B. $ 24 $ .
C. $ 12{{x}^{2}}y $ .
D. $ 12 $ .

Thực hiện phép nhân \[\left( {3{x^2}y - 6xy + 9x} \right)\left( { - \dfrac{4}{3}xy} \right)\] ta được kết quả
 
A.$ -4{{x}^{3}}{{y}^{2}}+8{{x}^{2}}{{y}^{2}}-12{{x}^{2}}y $. 
B.$ -4{{x}^{3}}{{y}^{2}}+8xy+12xy $.
C.$ -4{{x}^{2}}{{y}^{3}}-8xy-12{{x}^{2}}y $. 
D.$ -4{{x}^{3}}y-8xy+12{{x}^{2}}y $. 

Choose the word whose underlined part differs from the other three in pronunciation
A.speak
B.feat
C.threat
D.scream

Choose the word whose underlined part differs from the other three in pronunciation
A.proud
B.brow
C.how
D.blow

Choose the word whose underlined part differs from the other three in pronunciation
A.knee
B.knowledge
C.keep
D.knight

Choose the word whose underlined part differs from the other three in pronunciation
A.black
B.brace
C.branch
D.blanket

Choose the word whose underlined part differs from the other three in pronunciation
A.uncle
B.unique
C.university
D.union

Choose the word whose underlined part differs from the other three in pronunciation
A.pride
B.blight
C.bridge
D.blind