Our teacher told us that pollution _____ a very serious problem in the world we live.

A. has be
B. had been
C. is
D. was
C
請在這里輸入關(guān)鍵詞：
相關(guān)習題

科目：初中英語 來源：期末題 題型：單選題

Our teacher told us that pollution _____ a very serious problem in the world we live.

[     ]

A. has be
B. had been
C. is
D. was

查看答案和解析>>


同步練習冊答案