Câu hỏi: When mining for gold, you must first obtain the gold ore and then apart the gold from the ore.

A. When mining

B. must first

C. and then

D. apart

Câu 1: Looking from afar, the village resembles a small green spot dotted with tiny fireballs.

A. Looking

B. the village

C. dotted

D. fireballs

Câu 2: Dinosaurs became extinct millions of years ago because of the earth's climate changed drastically.

A. became extinct

B. because of

C. The earth’s

D. drastically

Câu 3: Because blood from different individuals may different in the type of antigen on the surface of the red cells and the type of antibody in the plasma, a dangerous reaction can occur between the donor and recipient in a blood transfusion.

A. Because

B. different

C. can occur

D. and

Câu 4: The Games' organizers faced significant bed shortages because the record number of more than 13,000 athletes and officials who attended the 2006 Games

A. faced

B. bed shortage

C. because

D. attended

Câu 5: Of all the art-related reference and research library in North America, that of the Metropolitan Museum of Art in New York City is among the largest and most complete.

A. Of all

B. reference and research

C. library

D. that of

Câu 6: How much times did Rich and Jennifer have to do the experiment?

A. much

B. did

C. have to

D. experiment