问题
选择题
_______the safety of gas, the government has checked the city's gas supply system thoroughly. [ ]
A. To ensure
B. Ensuring
C. Having ensured.
D. To have ensured
答案
答案：A
搜题请搜索小程序“爱下问搜题”
_______the safety of gas, the government has checked the city's gas supply system thoroughly. [ ]
A. To ensure
B. Ensuring
C. Having ensured.
D. To have ensured
答案：A