Which body system works with your digestive system to push your food along through your intestines

Spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

What molecules will be best used to compare different species with the exact same sequence of amino acids? why would two species have the same protein even if the molecules in question is different? (hint: transcription to translation to protein).

20 the compound al(nh3)2 has atoms of nitrogen.