3.As tomato season comes,we can clearly realize that tomatoes offered in supermarkets all the year round can't compare with those that are just picked.After all,the rule of keeping tomatoes fresh is not to refrigerate(冷藏)them,which means that any tomato transported from far away will never be as good as one that is just picked.
Researchers from the U.S Department of Agriculture say they're found an easy way to keep supermarket tomatoes tasting great:Heat them up first."To produce a better tasting tomato,we added a hot water pre-treatment step to the usual rule that growers follow,"Professor Jinhe Bai said."We found that this pre-treatment step prevents flavor loss because of being stored in refrigerators."
Because tomatoes often have a long way to go between being picked and reaching the supermarket shelves,farmers have to pick them while the fruit is green.The tomatoes are kept at a cold 41to 55degrees Fahrenheit during their trip to the store,which keeps them from producing enough enzymes(酶)that give tomatoes their smell and flavor.But when Bai and his team let green tomatoes sit in a bath of hot water for a few minutes,the tomatoes produced large amounts of the enzymes,keeping them tasty even after refrigeration.
The method isn't even the only one his group has experimented with.Growing green tomatoes with a kind of special oil or treating green tomatoes with a gas might also keep them fresh without having to be stored in refrigerators.
Bai even admits that refrigerated tomatoes can't hold a candle to fresh ones."Generally,tomatoes should be picked when they turned completely red and then sold immediately,"Bai says.
32.The method of keeping tomatoes fresh is toD.
A.put them in a bag with other fruits
B.a(chǎn)dd some special oil to refrigerators
C.wash them in hot water before eating them
D.put them in hot water before refrigerating them
33.Many green tomatoes are picked early to make sureD.
A.they can be easily stored
B.they taste better than red ones
C.they can be sold at a good price
D.they are still fresh in supermarkets
34.Why do tomatoes become less delicious after being kept in refrigerators?A
A.They don't produce enough enzymes.
B.The temperatures are not low enough.
C.The refrigerators also store other foods.
D.The flavor changes easily in closed spaces.
35.What can be inferred from Bai's words in the last paragraph?D
A.It's better to grow tomatoes by ourselves.
B.It's convenient to store tomatoes in refrigerators.
C.It's necessary to hold a candle when picking tomatoes.
D.It's impossible to keep tomatoes as fresh as they're just picked.