Apples and tomatoes are among the most popular agricultural products. However,
concerns have long been raised about the use of pesticides as they can accumulate in
our bodies    (16)      food is washed thoroughly before consumption. Traditional
methods of cleaning fresh produce, like fruit and vegetables, are based on rinsing with
water. The problem is that water may contain high amounts of chemicals such as
chlorine, chlorine dioxide, or ozone, which may be    (17)   the environment or
human health. Therefore, the development of environmentally friendly alternative
methods of cleaning fresh produce is important. One possible    (18)        is the
application of plasma for washing and drying fresh produce.
      Plasma can    (19)    a high amount of electricity and this is why in many
countries, it is already used to sterilize, or clean eggs. According to some agricultural
experts, plasma could potentially also be used to clean the surface of fruit, like melons,
mangos, and apples,    (20)    nut products with hard shells. More studies are needed
in this area but one day plasma could be used to benefit consumers who care both about
the environment and their own health.
【題組】16.
(A) unless
(B) otherwise
(C) however
(D) besides