We didn't complete (A) understand (B) the teacher's instructions (C). Most of (D) us did not finish the assignment.
A.complete (A)
B.understand (B)
C.instructions (C)
D.Most of (D)

When one experiences (A) a change in diet by, for example, moving (B) to a new location, you (C) may also experience (D) temporary problems with the digestive tract.
A.experiences (A)
B.moving (B)
C.you (C)
D.experience (D)

Rock music (A) was original (B) a mixture of country music (C) and rhythm and (D) blues.
A.Rock music (A)
B.original (B)
C.country music (C)
D.and (D)

We have to (A) study their (B) lessons more carefully if (C) we expect to pass (D) this examination.
A.have to (A)
B.their (B)
C.more carefully if (C)
D.to pass (D)

Although (A) the quantity was (B) small, they had supplies enough (C) to finish (D) the experiment.
A.Although (A)
B.was (B)
C.supplies enough (C)
D.finish (D)

Because (A) helicopters are capable of hovering (B) in midair, they are particular (C) useful for rescue missions, military operation (D), and transportation.
A.Because (A)
B.of hovering (B)
C.particular (C)
D.operation (D)

(Đề thi THPTQG-2017)
The government have established some wildlife reserves. They want to protect endangered species.
A.Whether the government have established some wildlife reserves or not, endangered species are still protected.
B.Endangered species can't be protected although the government have established some wildlife reserves.
C.The government have established some wildlife reserves so that endangered species can be protected.
D.If the government established some wildlife reserves, they would be able to protect endangered species.

(Đề thi THPTQG-2017)
My sister is good at cooking. My brother is bad at it.
A.My sister is good at cooking, or my brother is bad at it.
B.My sister is good at cooking, for my brother is bad at it.
C.My sister is good at cooking, but my brother is bad at it.
D.My sister is good at cooking, so my brother is bad at it.

Choose the underlined part that needs correction.Although maple trees are among (A) the most colorful varieties in the fall (B), they lose its (C) leaves sooner than (D) oak trees.
A.among (A)
B.in the fall (B)
C.its (C)
D.sooner than (D)

The (A) number of citizens that (B) traveled by (C) bus increased significant (D) in 2006.
A.The (A)
B.that (B)
C.by (C)
D.significant (D)