问题 选择题

青少年要注意坐、立、行的姿势,从生物学上分析,主要是因为(  )

A.青少年的骨,有机物含量大于

1
3
,容易变形

B.青少年好动,不注意就容易骨折

C.姿势正确才不会被人笑话

D.青少年的骨,无机物含量大于

2
3,容易骨折

答案

骨的成分包括有机物和无机物,有机物越多,骨的柔韧性越强,无机物越多,骨的硬度越大;在不同时期,骨的成分不同,如下表:

所以在儿童青少年的骨中,有机物多于1/3,骨的弹性大,容易变形,所以青少年要注意坐、立、行的姿势.

故选A

单项选择题

Strange things have been happening to England. Still (1) from the dissolution of the empire in the years (2) World War Ⅱ, now the English find they are not even British. As the cherished "United Kingdom" breaks into its (3) parts, Scots are clearly (4) and the Welsh, Welsh. But who exactly are the English What’s left of them, with everything but the (5) half of their island taken away

Going back in time to (6) roots doesn’t help. First came the Celts, then the Romans, then Angles, Saxons, Jutes, Danes. Invasion after invasion, until the Norman Conquest. English national identity only seemed to find its (7) later, on the shifting sands of expansionism, from Elizabethan times onwards. The empire seemed to seal it. But now there’s just England, (8) of a green island in the northern seas, lashed by rain, scarred by two (9) of vicious industrialization fallen (10) dereliction, ruined, as D.H. Lawrence thought, by "the tragedy of ugliness," its abominable architecture.

Of all English institutions, the one to (11) on would surely be the pub. Shelter to Chaucer’s pilgrims, home to Falstaff and Hal, throne of felicity to Dr. Johnson, the pub- that smoky, yeasty den of jollity-is the womb of (12) , if anywhere is. Yet in the midst of this national (13) crisis, the pub, the mainstay of English life, a staff driven (14) into the sump of history, (15) as the Saxons, is suddenly dying and evolving at (16) rates. Closing at something like a rate of more than three a day, pubs have become (17) enough that for the first time since the Domesday Book, more than half the villages in England no longer have one. It’s a rare pub that still (18) , or even limps on, by being what it was (19) to be: a drinking establishment. The old (20) of a pub as a place for a "session," a lengthy, restful, increasingly tipsy evening of swigging, is all but defunct.

2()

A.before

B.followed

C.following

D.with

填空题