In most cases, you can transplant a tree successfully, at any time, if you follow the instructions for planting a tree. The most important thing is to dig out enough roots, but this process is difficult with a large tree.
When you dig out the tree, leave a ball of earth around its roots. This ball of earth should measure about a foot wide for every inch of the tree trunk’s diameter. Dig deep enough to avoid cutting off too many taproots.
It is wise to call in a professional tree expert to transplant a tree more than a few inches in trunk diameter.
[听力原文]
Here are little cars that may some day take the place of today’s cars. If everyone drives such a car in the future, there will be less pollution in the air. There will also be more parking spaces in cities, and the streets will be less crowded. Three such cars fit in the space now needed for one car of the usual size. The little cars will cost much less to own and to drive. Driving will be safer, too, as these little cars can go only 55 miles per hour. The cars of the future will be fine for getting around a city, but they will not be useful for long trips.
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