1‘she's normally very placid’
even-tempered, calm, equable, tranquil, imperturbable, unexcitable, peaceable, peaceful, serene, mild, gentle, quiet, cool, cool-headed, collected, cool, calm, and collected, composed, self-possessed, poised, easy-going, temperate, level-headed, steady, unruffled, unmoved, undisturbed, unperturbed, unemotional, phlegmatic, stolid, bovine
2‘the placid waters of a small lake’
quiet, calm, tranquil, still, peaceful, motionless, smooth, waveless, pacific, unruffled, undisturbed, like a millpond
We take a look at several popular, though confusing, punctuation marks.