What English proverb is the Spanish "No hay tiempo como el presente"?

A prosthesis is an artificial replacement for which kind of body part, such as an arm or leg? What protective coat does a scientist often wear? What is the protruding part of the face below the lips? What word describes a proud, stiff, pompous walk? What English proverb is the Spanish "Pensar antes de hablar"? A proverb says "Make yourself all ___ and the flies will devour you." What word? A proverb says that which seldom knocks twice? Which energy services company has traded on the stock exchange as HAL?