1. It is also important to have something that can clean water and kill bacteria, so water from other sources can be made safe to drink.
    储备一些可以净化水和消灭病菌的东西也很重要，这样就可以安全饮用其他来源的水了。

2. First, older exercisers should be sure to check with a doctor to make sure any new exercise program is safe and appropriate.
    第一，老年运动者应该接受医生的检查，以确保新的锻炼计划安全合理。