isaac is investigating how long it takes his dog to react to different sounds. what is the independent variable?

Anton created a chart listing different types of materials. which best complete the chart?

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

When does a spring tide occur? question 9 options: they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur twice a year in the spring and fall. they occur on the date of the vernal equinox each year, no matter what stage the moon is in. this is why they are called spring tides. they occur when the sun, moon, and earth are at 45-degree angles from each other. this happens once every spring. they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur all year long.