问题
选择题
Let's go to Mr Wang for help, _______ our work can't be finished in time.[ ]
A. and
B. or
C. but
D. so
答案
答案：B
搜题请搜索小程序“爱下问搜题”
Let's go to Mr Wang for help, _______ our work can't be finished in time.[ ]
A. and
B. or
C. but
D. so
答案：B
]来衡量过碳酸钠产品的优劣，13%以上者为优等品。