Số a thích hợp để \[ - \frac{{27}}{{343}} = {\left( { - \frac{3}{7}} \right)^a}\] là
A. $ 1 $ .
B. $ 7 $ .
C. $ 2 $ .
D. $ 3 $ .

Chọn đáp án đúng.
A. $ 16={{2}^{5}}. $
B. $ 243={{4}^{5}}. $
C. $ -\dfrac{27}{343}={{\left( -\dfrac{3}{7} \right)}^{3}}. $
D. $ 0,0001={{\left( -0,1 \right)}^{3}}. $

Giá trị $ x $ thỏa mãn $ {{3}^{x}}+{{3}^{x+2}}=810 $ là
A. $ x=2 $ .
B. $ x=4~ $ .
C. $ x=-4 $ .
D. $ x=8 $ .

Giá trị $ x $ thỏa mãn $ {{\left( \text{x}\,-\dfrac{\text{1}}{\text{2}} \right)}^{\text{3}}}\text{ = }\dfrac{\text{1}}{\text{27}}\text{ } $ là
A. $ -\dfrac{1}{6} $ .
B. $ -\dfrac{5}{6} $ .
C. $ \dfrac{5}{6} $ .
D. $ \dfrac{1}{6} $ .

Giá trị $ {{\left( 0,125 \right)}^{4}}.\text{ }{{8}^{4}}~ $ bằng
A. $ 10 $ .
B. $ 1000 $ .
C. $ 100 $ .
D. $ 1 $ .

Kết quả phép tính $ \dfrac{{{90}^{2}}}{{{15}^{2}}} $ bằng
A. $ 6 $ .
B. $ 26 $ .
C. $ 16 $ .
D. $ 36 $ .

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
We are looking for _______ hotel to spend ________ night.
 
A.a/a
B.the/the
C.the/a
D.a/the

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
Anna lives on _________ top floor of _______ old buiding.
A.a/an
B.the/the
C.the/an
D.the/a

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
Recently I have seen several air-crash. Therefore, I’d rather travel by …………….
A.train
B.helicopter
C.plane
D.hot air balloon

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
With the existence of flying cars, I think there will be less traffic …………….in the future.
A.cars
B.jam
C.vehicle
D.road