Find a mistake in the four underlined parts of the sentence and correct it:
Such human activities as pollution, drainage of wetlands, cutting and clearing of forests, urbanization, and road
and dam construction has destroyed or seriously damaged available habitats.
A. Such
B. drainage
C. clearing
D. has destroyed

Find a mistake in the four underlined parts of the sentence and correct it:
Mr. Lam wasn’t well, but even though of this he didn’t stay in hopital.
A. well
B. but
C. even though
D. didn’t stay

Find a mistake in the four underlined parts of the sentence and correct it:
All travel arrangements must complete by June 17 .
A. All
B. arrangements
C. complete
D. by

Find a mistake in the four underlined parts of the sentence and correct it:
A driver’s license can obtain from the licensing Bureau at the comer of Pine street.
A. driver’s
B. can obtain
C. the
D. at the comer

Find a mistake in the four underlined parts of the sentence and correct it:
The road is in very bad condition. It should be repaired a long time ago.
A. is in
B. bad
C. should be
D. a long time

Find a mistake in the four underlined parts of the sentence and correct it:
Cars of the future will be using advanced technology to perform such functions as automatic cruise control,
hazardous object avoidance, self-parking but driverless transportation.
A. will be using
B. advanced
C. perform
D. but

Cho tứ diện $\displaystyle ABCD$ và điểm$\displaystyle G$ thỏa mãn$\overrightarrow{GA}+\overrightarrow{GB}+\overrightarrow{GC}+\overrightarrow{GD}=\overrightarrow{0}$ ($\displaystyle G$ là trọng tâm của tứ diện). Gọi$\displaystyle {{G}_{O}}$ là giao điểm của$\displaystyle GA$ và mp$\displaystyle (BCD)$. Trong các khẳng định sau, khẳng định nào đúng?
A. $\overrightarrow{GA}=-2\overrightarrow{{{G}_{0}}G}$.
B. $\overrightarrow{GA}=4\overrightarrow{{{G}_{0}}G}$.
C. $\overrightarrow{GA}=3\overrightarrow{{{G}_{0}}G}$. 
D. $\overrightarrow{GA}=2\overrightarrow{{{G}_{0}}G}$.

Kết quả của giới hạn $\displaystyle \,\underset{x\to {{\left( -1 \right)}^{+}}}{\mathop{\lim }}\,\left( {{x}^{3}}+1 \right)\sqrt{\frac{x}{{{x}^{2}}-1}}$ là 
A. $3.$ 
B. $+\infty .$ 
C. $0.$ 
D. $-\infty $

Cho hai vectơ $\overrightarrow{a},\overrightarrow{b}$ thỏa mãn:$\displaystyle \left| \overrightarrow{a} \right|=4;\left| \overrightarrow{b} \right|=3;\overrightarrow{a}.\overrightarrow{b}=10$. Xét hai vectơ$\overrightarrow{y}=\overrightarrow{a}-\overrightarrow{b}$,$\overrightarrow{x}=\overrightarrow{a}-2\overrightarrow{b},$. Gọi α là góc giữa hai vectơ$\overrightarrow{x},\overrightarrow{y}$. Chọn khẳng định đúng.
A. $\cos \alpha =\frac{-2}{\sqrt{15}}$. 
B. $\cos \alpha =\frac{1}{\sqrt{15}}$. 
C. $\cos \alpha =\frac{3}{\sqrt{15}}$.
D. $\cos \alpha =\frac{2}{\sqrt{15}}$.

Đạo hàm bên phải và bên trái của hàm số: f(x) = l x l - l x + 1 l tại x0 = 0 bằng
A. f'(0+) = -1; f'(0-) = -1.
B. f'(0+) = -1; f'(0-) = -2.
C. f'(0+) = 0; f'(0-) = -2.
D. f'(0+) = 1; f'(0-) = -2.