maser

n device for producing or amplifying microwaves 微波激射器.

martinet, Martini (also martini), martyr, martyrdom, marvel, marvel at, marvellous, marvellous (US marvelous), marvellously (US marvelously), marvelous, Marxism, Marxism-Leninism, Marxist, Marxist-Leninist, marzipan, masc, mascara, mascot, masculine, masculinity, mash, mask, masked ball, masking tape, masochism, masochist, masochistic, mason, masonic (also Masonic), masonry, masque, masquerade, masquerader, mass, Mass (also mass), mass communications, mass hysteria, mass media, mass-produce, Massachusetts,