Did admiral yamamoto make a wise decision in bombing pearl harbor? why or why not?

What is the meaning of the statement that all is vanity or meaningless? use full sentences

The system of checks and balances ensures that

Ascientist performs an experiment where she measures the mass of a piece of metal, pours acid onto the metal, washes the metal, and then re-measures the mass of the metal. the scientist repeats the experiment several times, each time increasing the amount of acid used. the dependent variable in the experiment is the: initial mass of the metal final mass of the metal amount of acid used washing the metal