Air column: space within the percussion instrument that determines the pitch. Percussion: sounds produced by striking the instrument with a mallet or stick, or striking one instrument against another. 2. Review the process of forming a hypothesis and making a prediction.
Dig short, shallow rows. The rows should be no more than 1/2 inch (1.5 centimeters) deep and spaced 4 inches (10 centimeters) to 6 inches (15 centimeters) apart. 3. Drop the seeds into the rows. Space the seeds approximately 1 inch (25 millimeters) apart in order to allow the onions enough room to grow and mature.
1 The easiest way to grow onions is from sets, available from garden centres. 2  Prepare the soil a couple of months before planting by digging over and adding manure. 3  Plant the sets in spring in shallow drills and cover them so the necks are just protruding from the soil.