退出测验
英语测试
〉
单项选择
〉
《英语专业四级（TEM4）模拟卷语法与词汇部分12》
您目前参加的是临时答题模式。立即点击注册，获得更多功能
Most environmental problems exist because adequate measures for preventing them___taken in the past.
A. was not
B. were not
C. were not being
D. being not
下一题