2 Al + 6 HCl → 2 AlCl₃ + 3 H₂ (single displacement)
Ca + Br₂ → CaBr₂ (synthesis)
4 NH₃ + 5 O₂ → 4 NO + 6 H₂O (combustion)
2 NaCl → 2 Na + Cl₂ (decomposition)
FeS + 2 HCl → FeCl₂ + H₂S (double displacement)
single displacement - is a chemical reaction of the following type: A + BC → AC + B
double displacement - is a chemical reaction of the following type: AB + CD → AC + BD
synthesis - the chemical product is obtained by combining in a synthesis the constituent elements
combustion - usually a exothermic reaction of a particular compound with oxygen
decomposition - degradation of a compound in simpler elements
Cellular respiration can be thought of as the opposite of photosynthesis. In cellular respiration oxygen is turned into carbon dioxide while in photosynthesis carbon dioxide is tuned to oxygen.
I hope this helps. let me know in the comments if anything is unclear.
A, because the shape of it forms and arc much like a H2O molecule.
You should clean up after every investigation because if you leave a mess, maybe another detective will come in and get lost because of the mess you left.