It is only one nuclei in a cell
The answer is B. Water/H2O
The answer is C. Enzymes lower activation energy, allowing the reaction to happen more quickly, which is why they are called catalysts.
A major problem in sending space probes to Jupiter is that the planet has no solid surface on which to land, as there is a smooth transition between the planet's atmosphere and its fluid interior. Any probes descending into the atmosphere are eventually crushed by the immense pressures within Jupiter
