A.97% B.98% C.99% D.100%
A.6 B.9 C.12 D.15
A.釋放氧氣,防止二氧化碳進(jìn)入 B.釋放二氧化碳,防止氧氣進(jìn)入 C.保質(zhì)期是34周 D.保質(zhì)期是36周