Answer:
7. <u><em>Don't consider running a marathon unless you are in good physical condition.</em></u>
8. <u><em>Don't leave training until just before the marathon in case you might injure yourself.</em></u>
9. <u><em>Take time off from running every week otherwise, your body will not have a chance to rest.</em></u>
10. <u><em>As long as you train carefully, you can avoid injury.</em></u>
11. <u><em>Assuming you are sensible, you should run a marathon safely and successfully.</em></u>
Explanation:
Rewriting the sentence using the words given in the brackets means structuring the sentence to retain the meaning but make a new sentence. The new sentences after their restructuring are given as below-
<u><em>7. Don't consider running a marathon unless you are in good physical condition.
</em></u>
<u><em>8. Don't leave training until just before the marathon in case you might injure yourself.
</em></u>
<u><em>9. Take time off from running every week otherwise, your body will not have a chance to rest.
</em></u>
<u><em>10. As long as you train carefully, you can avoid injury.
</em></u>
<u><em>11. Assuming you are sensible, you should run a marathon safely and successfully.</em></u>