单项选择题

Food deteriorates during storage because ______.

A．necessary chemical preservatives are totally absent from it
B．it is infected with yeasts, moulds and bacteria
C．heat sterilization destroys infections present in it
D．it isn't fit for storage

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热门试题

单项选择题

All of the following are the steps of canning food except ______.

A．cleaning and trimming raw food
B．sterilizing canned food
C．blanching vegetables that are to be canned
D．printing labels and packing the tins into boxes

单项选择题

According to the passage, after the average per-minute cost dropped to 11 cents this year from 56 cents in 1995, the phone companies ______.

A．attracted more and more new users and as a result, they began to flourish
B．began to suffer from a great loss
C．made traditional phones more popular
D．invested much more money in creating new phones