Nothing great was ever achieved without enthusiasm. ~ralph waldo emerson. what does it mean?

Read the passage: canines may not be the deepest thinkers in the world. but perhaps that's for the best. the life of a dog—sitting alone all day, waiting for everyone to come home—can be pretty boring. super-smart animals would probably get totally stressed out, says university of pennsylvania researcher james serpell. look at it this way: if dogs were any smarter, they probably wouldn't choose to hang around with us. which best describes the tone of the passage?

Acomplex sentence contains . one subject and one verb

Which statement is most clearly objective?