You ______ do it even if you don't want to.[ ]
A. can't
B. mustn't
C. have to
D. needn't
C
由于财政赤字增加了政府支出而挤出了民间支出的现象叫()。
当怀疑混凝土内外质量有明显差异时,可用回弹法检测。