Milk will turn sour soon on hot days ___
题型:选择题
问题:
Milk will turn sour soon on hot days ______ it is stored in the refrigerator.
A.since
B.until
C.because
D.unless
Milk will turn sour soon on hot days ______ it is stored in the refrigerator.
A.since
B.until
C.because
D.unless