刚刚装修的房子由于材料中含有害物质甲醛（CH₂O）,一进门就会感觉刺眼，这是由于分子          使空气中充满了甲醛。为了减少危害，通常会在家中放置一些活性炭，这是利用活性炭的             。

Ink-jet printer belongs to nonimpact printers in which the characters are formed by projecting particles or droplets of ink on to paper. (71) printer is also a nonimpact printer in which the characters are produced by applying hot elements to heat-sensitive paper directly or by melting ink from a (72) on to plain paper. Electrostatic printer creates an electrostatic latent image, which is then made visible by a toner and transferred and fixed on paper. An electrostatic printer may be used in some instances as a (73) . Laser printer creates, by means of a laser beam directed on a (74) surface, a latent image which is then made visible by a toner and transferred and fixed on paper. Magnetographic printer creates, by means of magnetic heads operating on a metallic drum, a latent image which is then made visible by a toner and transferred and fixed on paper. Computer-output-microfilm (COM) printer produces on a photographic film a (75) of each page.

（74）处填（）。

A．brightness

B．photosensitive

C．emitter

D．light-sensitive