Câu hỏi: 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 1: He has made a lot of mistakes in his writing because his carelessness.

A. made

B. mistakes

C. in

D. because

Câu 2: 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 3: People are not allowed enter the park after midnight because of lack of security.

A. allowed enter

B. after

C. because of

D. of

Câu 4: 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 5: When precipitation occurs, some of it evaporates, some runs off the surface it strikes, and some sinking into the ground.

A. When

B. it

C. runs off

D. sinking

Câu 6: In the early 1900's, Pennsylvania's industries grew rapidly, a growth sometimes accompanied by disputes labor.

A. the early 1900’s

B. industries

C. accompanied by

D. labor