问题
选择题
The film you'd like to quickly won't be ready until tomorrow morning. [ ]
A. have develop
B. have developed
C. have to develop
D. have to be developed
答案
答案：B
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The film you'd like to quickly won't be ready until tomorrow morning. [ ]
A. have develop
B. have developed
C. have to develop
D. have to be developed
答案：B
其反应式是3C+2 K2Cr2O7+ 8H2SO4 3CO2↑+2K2SO4+2Cr2(SO4)3+8H2O