irradiating（照射）fruits, vegetable, pork and chickento kill insects and bacteria has been approved by the Food and DrugAdministration over the past decade or

so.Irradiation ofother meats, such as beef and lamb,is being reviewed.Federal approval dose notrequire that industry adopt the process,and few food processors presently

offer irradiatedproducts.

Market studies haveshown that many consumers are afraid that eating irradiated food may causecancer,despite scientific studies that prove the safety of treated food.Some

people argue thatmore severe government inspection,higher food-safety standards,and more carefulfood-preparation practices by consumers are all that is needed to ensure

that food issafe.Consequently,companies currently see no need to spend millions of dollarsoutfitting（配备）processingplants with the equipment necessary for a process

that very fewshoppers are in favor of.

All supermarketsthat sell irradiated food must label that food either directly on the packagingor in the case of bulk items like fruits and vegetables by placing a signnearby.

There is norequirement for the labeling of irradiated food served by chain restaurants orhospitals that buy directly from distributors,nor any regulations for productsthat

contain irradiatedingredients.

Presently,the FDAallows food to be treated with three types of radiation一gamma rays,highenergy electrons,andX-rays,and sets limits on doses（辐射量）depending on the

type of food. Theprinciple is that the dose to be used for a certain type of food should notexceed the amount that is sufficient to kill most harmful insects and bacteriapresent

in it.Differenttypes of food,because of their different molecular（分子）compositions,may require differentdoses of radiation.According to thepassage,killing insets and bacteria present in food by irradiating_________.

A.has beencompletely approved by the FDA

B.is being reviewedby the FDA

C.is not completelyapproved by the U.S.government

D.has been widelyadopted in the U.S.