Studies show that trees and plants improve air ______________ which is very bad now because of the traffic.

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.

Studies show that trees and plants improve air ______________ which is very bad now because of the traffic.

A. quantity

B. atmosphere
C. amount
D. quality

Trả lời

Chọn D

Câu hỏi cùng chủ đề

Xem tất cả