Good pencil erasers are soft enough not __
题型:单项选择题
问题:
Good pencil erasers are soft enough not ________paper but hard enough so that they crumble gradually when used.
A.by damaging
B.so that they damage
C.to damage
D.damaging
Good pencil erasers are soft enough not ________paper but hard enough so that they crumble gradually when used.
A.by damaging
B.so that they damage
C.to damage
D.damaging