Is it anh?
hope this helps
<span>
When you excersise, your target heart rate should be between 25% to 70% of your maximum heart rate. Your target heart rate r at 70% can be determined by the formula r=0.7(220-a) where a represents your age in years. Solve the formula for a.</span>
A nebula is an enormous cloud of dust and gas occupying the space between stars and acting as a nursery for new stars. The roots of the word come from Latin nebula, which means a “mist, vapor, fog, smoke, exhalation.” Nebulae are made up of dust, basic elements such as hydrogen and other ionized gases.
