英音 [ˈfəʊkəs] 美音 [ˈfoʊkəs]
vt.& vi. （使）集中，（使）聚集;调整（镜头，眼睛）焦点[焦距]以便看清;
the concentration of attention or energy on something;
"the focus of activity shifted to molecular biology"
"he had no direction in his life"
maximum clarity or distinctness of an image rendered by an optical system;
"out of focus"
maximum clarity or distinctness of an idea;
"the controversy brought clearly into focus an important difference of opinion"
a central point or locus of an infection in an organism;
"the focus of infection"
special emphasis attached to something;
"the stress was more on accuracy than on speed"
a point of convergence of light (or other radiation) or a point from which it diverges
a fixed reference point on the concave side of a conic section
direct one's attention on something;
"Please focus on your studies and not on your hobbies"
cause to converge on or toward a central point;
"Focus the light on this image"
bring into focus or alignment; to converge or cause to converge; of ideas or emotions
become focussed or come into focus;
"The light focused"
put (an image) into focus;
"Please focus the image; we cannot enjoy the movie"
defocus v. 使散焦，使散开;使焦点模糊;