Pls answer lol What is a major threat facing intertidal zone ecosystems?

pollution caused by human activities

the mysterious disappearance of phytoplankton

exceptionally high or low tides

habitat destruction caused by hurricanes

Avariable that is not being directly tested during an experiment should be changed varied experimented controlled

Can someone me with 6 to 10 plz this is for masteries test.

Which of your 24 wells had indications that a chemical reaction occurred? how were you able to tell that a chemical reaction occurred? which of your 24 wells had indications that a physical reaction occurred? how were you able to tell that a physical reaction occurred? report on both mixing and evaporation. make a general statement about whether your hypotheses were validated or rejected. must your hypotheses be correct for this to be a successful laboratory?