A fantastic idea occurred to him ________ he could use a plastic bottle, ________ cut off, as a container to grow young plants in.
31. The chair looks rather hard,but in fact it is very comfortable to________.
30. Wang Tao was made_______ the dishes for a week as a punishment.
29. When I handed the report to John,he said that George was the person______.
28.Although _____ to stop, he kept on working.
27.The question _______ at present has something important to do with our nature.