语法填空。
If you walked past the supermarket, you would find many foods that have been treated 1_____ (kill) any
harmful germs that might have been in them. Milk is a good example. Raw milk-that is, milk just as it comes
from the cow-may be 2_____ (safe) to drink. But 3_____ the milk is heated and then cooled, the harmful
germs are killed. The man 4_____ discovered this way of treating milk was a Frenchman by the name of
Louis Pasteur.
In the supermarket you would also find many frozen foods-frozen fruits, vegetables, meat and fish. As
techniques for 5_____ (freeze) food are being improved, more frozen foods are appearing on the market,
and more people are buying them. Fruits and vegetable to be sold in the supermarket are often frozen the
moment 6_____ are picked. The 7_____ fruits and vegetable are frozen, the better. 8_____ machines are
often taken into the fields where 9_____ food grows, so that little time is lost 10_____ picking and freezing.
