A will be the answer because usually marking your exercise days will become a habit because lets say you would do a running exercise but you want to do it in a certain day well if you mark it on the calendar, it'll become a habit.
The most important nutrients for people with osteoporosis are calcium and vitamin D. Vitamin D helps your body to absorb calcium.
Answer:Both of these materials emit numerous volatile organic compounds (VOCs), many of them toxic. In addition to VOCs, the printing process generates nano particles which pose a respiratory hazard. More novel applications involve the printing of biological scaffolds used to generate organs and other structures.
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