It is clear that no use can be made ____
题型:选择题
问题:
It is clear that no use can be made ______radium _____ we don’t know clearly the characteristics of it. [ ]
A. from; if
B. of; unless
C. from; unless
D. of; if
It is clear that no use can be made ______radium _____ we don’t know clearly the characteristics of it. [ ]
A. from; if
B. of; unless
C. from; unless
D. of; if