表面活性剂的增溶作用,是由于形成了
A. 络合物
B. 胶束
C. 包合物
D. 复盐
I won’t call you, ________ something unexpected happens.
A. unless
B. whether
C. because
D. while
_______ he had not hurt his leg, John would have won the race.
A. If
B. Since
C. Though
D. When
Small sailboats can easily turn over in the water ______ they are not managed carefully.
A. though
B. before
C. until
D. if