A Case Study On Fumigants · Part 4 · 第 31–40 题
Complete the notes below. Write ONE WORD ONLY for each answer.
Complete the notes below. Write ONE WORD ONLY for each answer.
A CASE STUDY ON FUMIGANTS
Problems with traditional fumigation
• Some chemicals released during fumigation may damage the Earth’s 31 layer.
• After methyl bromide treatment, paintings may lose some of their original 32 .
• To prevent dangerous gas from escaping, food can be placed inside a sealed 33 .
• In countries with humid conditions, the treatment is often more 34 because additional equipment is required.
An alternative treatment
• Researchers created an environment containing almost no oxygen.
• The total 35 period used in the experiment lasted fourteen days.
• Air was removed from the sealed space and replaced with 36 .
• The new method was tested on an old wooden 37 that had been attacked by insects.
• The treatment killed the insects without causing visible damage to the object.
A possible biological solution
• Scientists have examined protective substances found in the skin of certain 38 .
• These natural chemicals behave in a similar way to 39 , as they destroy harmful organisms.
• One current limitation is that the substances become less effective when exposed to 40 .