How do pyrotechnicians control the timing so that the firework doesn't explode until it is 500 feet in the sky?

What is the name of the protein that gives the nucleus its shape? Why did Brahmaputra river take a turn and come to India? Latitude is based on the celestial observation of? What is the main cause of transpiration? Occurs as food is broken down both chemically and mechanically? What does an organism do after it gets energy from food? How would you create a black pigment? What test would be useful to differentiate between the two genera if you see Gram positive cocci under the microscope but you cant quite tell the arrangement of the cells? What does a Richard scale do? Are there glaciers on Fiji island mountains? What are not dangers of a hurricane? What is the smallest type of removable media called? How many liters run from a faucet In a minute? What has the global impact of television been? How do humans ruin the Greenhouse effect? How long in years would take to travel 57 trillion km in light years? What does an -ite or -ate ending in a polytomic ion mean? Why salvia sepals are described as petaloid? The 8 planets in order of nearest to the sun? When does a plant's life cycle end?