If my problem statement is: Which mask filters air more effectively?

And my independent variable is: Type of mask

What's my dependent variable?

What is the ima of the 1 st class lever in the graphic given? 2 3 0.5

Which of the following is most likely true about water in chemical solutions?

Harry lives in a city, and he has a lung condition known as asthma. on certain days, harry has to stay inside because pollutants in the air make it difficult for him to breathe. which of these pollution sources are nonpoint sources that might bother harry if he goes outside? choose the two that apply.