Which of the following puts the secondary treatment of wastewater in the correct order?
bacteria settle in clarifier; aeration tank is churned and bacteria eat- water is flowed into the tank and air is pumped into it.
bacteria multiply and eat waste in settler- water is circulated and air is added to the system; bacteria then are added to the aeration tanks.
bacteria seeded in aeration tank as air is circulated throughout the water- bacteria multiply and eat waste; bacteria settle in clarifier.
clarifier is added to the aeration tanks; bacteria thrive and eat waste- air is added to the end to mix the sludge.

The organelle pictured is found in cells of and is theorized to have once been an independent organism.

Consider the motion of the balloon and its air contents in terms of momentum. in step 1 above, the total momentum of the balloon and its contents was zero. recall that momentum = mv. both the balloon and the air inside it had a velocity of zero and therefore the total momentum was zero. now think about what happened when the air escaped from the balloon. a certain mass of air accelerated in one direction. in order to keep the total momentum of the system zero, the balloon itself (which has mass) had to accelerate in the opposite direction. use this scenario to you explain why the soda can rotates when the water squirts out of the escape holes. what was your hypothesis concerning the water-filled can? according to your data, do you think your hypothesis was correct? (be sure to refer to your data when answering this question.) summarize any difficulties or problems you had in performing the experiment that might have affected the results. describe how you might change the procedure to avoid these problems. give at least one more example of newton's third law in everyday life.

Humans are believed to have evolved in coastal regions in east africa. the region had an abundant supply of fish for early humanoids to eat. when scientists analyze the fads gene they see an interesting pattern. people whose families have lived in this area of east africa for generation show a high level of diversity in alleles for the fads gene. conversely, people whose families had migrated inland a moderate distance from sources of fish showed a much lower diversity for fads gene alleles. additionally, the fads alleles found in people whose family has lived inland for generation are almost all gene alleles which produce fads proteins with a high level of function and activity. how do anthropologists explain this?