Ava’s best friend has an indoor cat. ava notices that she sneezes every time that she visits her friend. ava suspects that she is allergic to cats but is unsure. what is the best thing for ava to do next? stop visiting her friend. conclude that she is allergic to cats, and avoid them completely. test her suspicion by checking to see whether other cats also make her sneeze. assume that the sneezing has another cause, and reject her original idea.

In which situation has the independent variable for the experiment been changed? check all that apply. changed from counting the number of duckweed at day 0 and day 14 to counting them every day changed from testing duckweed growth in beakers to testing duckweed growth in large outdoor tanks changed from testing the effect of ph on duckweed growth to testing the effect of light levels on duckweed growth changed from testing the effect of acid ph on duckweed growth to testing the effect of basic ph on duckweed growth

Why is it important always to use horizontal bars in unit fractions when performing unit conversions?

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?