The vegetative forms of most bacteria are killed by drying in air, although the different species exhibit pronounced differences in their resistance. The tubercle bacillus is one of the more resistant, and vibrio cholera is one of the more sensitive to drying. In general, the encapsulated organisms are more resistant than the non-encapsulated forms. Spores are quite resistant to drying; the spores of the anthrax bacillus, for example, will germinate after remaining in a dry condition for ten years or more. The resistance of the pathogenic forms causing disease of the upper respiratory tract is of particular interest in connection with airborne infection, for the length of time that a droplet remains infective is a result, primarily, of the resistance of the particular microorganism to drying. |
The vegetative forms of most bacteria are killed by drying in air, although the different species exhibit pronounced differences in their resistance. The tubercle bacillus is one of the more resistant, and vibrio cholera is one of the more sensitive to drying. In general, the encapsulated organisms are more resistant than the non-encapsulated forms. Spores are quite resistant to drying; the spores of the anthrax bacillus, for example, will germinate after remaining in a dry condition for ten years or more. The resistance of the pathogenic forms causing disease of the upper respiratory tract is of particular interest in connection with airborne infection, for the length of time that a droplet remains infective is a result, primarily, of the resistance of the particular microorganism to drying. |
Most new words are made up from other
earlier words; language-making is a conservative process, wasting little. When
new words unfold out of old ones, the original meaning usually hangs around like
an unrecognizable scent, a sort of secret. There are two immense words from Indo-European, gene and bheu, each a virtual anthill in itself, from which we have constructed the notion Of everything. At the beginning or as far back as they are traceable, they meant something like being. Gene signified beginning, giving birth, while bheu indicated existence and growth. Gene turned itself successively into kund jaz (Germanic) and gecynd (Old English), meaning kin or kind. Kind was at first a family connection, later an elevated social rank, and finally came to rest meaning kindly or gentle. Meanwhile, a branch of gene became the Latin gens A. how to coin new words B. where to trace the origin of language C. the evolution of words D. language and nature [单项选择]Passage Two
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