M: Do you think that you can have these shirts finished by Friday morning W: I ’ m sorry. I couldn ’ t possibly get them done by then. Saturday afternoon would be the earliest when you could have them When will the shirts be finished?
【简答题】食品保鲜可以防止食品腐坏,保持食品的营养和味道.食品保鲜的措施有添加防腐剂、充填气体、放置干燥剂和脱氧保鲜剂等. (1)包装熟食制品常加入防腐剂.丙酸钠是一种食品防腐剂,化学式为C 3 H 5 O 2 Na,丙酸钠是由______种元素组成,其相对分子质量为______; (2)小包装糕点类食品常采用充气包装,氮气是常用的充填气体.请你根据氮气的性质写出选用氮气的主要原因是______; (3)生...
【简答题】食品保鲜可以防止食品腐坏,保持食品的营养和味道。食品保鲜的措施有添加防腐剂、充填气体、放置干燥剂和脱氧保鲜剂等。 (1)包装熟食制品常加入防腐剂。丙酸钠是一种食品防腐剂,化学式为C 3 H 5 O 2 Na,丙酸钠是由_________种元素组成,其相对分子质量为_________; (2)小包装糕点类食品常采用充气包装,氮气是常用的充填气体。请你根据氮气的性质写出选用氮气的主要原因是______...