由于乳剂的分散相和连续相比重不同，造成上浮或下沉的现象称

A．絮凝

B．乳析

C．分层

D．转相

E．破乳

The only solution to rubbish problem for a nation which now spends more on wrapping food than it pays farmers to produce it, is recovering______the packaging materials for commer cial as well as for conservation reasons.

A．on sale

B．on the spot

C．on a large scale

D．on all sides