试题与答案

从某建筑物顶部自由下落的物体，在落地前的1秒内下落的高度为建筑物高的3/4，则物

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题型：选择题

题目：

从某建筑物顶部自由下落的物体，在落地前的1秒内下落的高度为建筑物高的3/4，则物体落到地面的瞬时速度为（　　）

A．10m/s

B．15m/s

C．20m/s

D．25m/s

答案：

假设总时间是t，则：

全程：h=

1
2
gt2

前

1
4
h过程：
1
4
h=
1
2
g(t-1)2

联立解得

t=2s

故落地速度为：v=gt=20m/s

故选C．

考点：自由落体运动
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     Teaching children to read well from the start is the most important task of elementary schools. But relying

on educators to approach this task correctly can be a great mistake. Many schools continue to employ

instructional methods that have been proven ineffective. The staying power of the "look-say" or "whole-word"

method of teaching beginning reading is perhaps the most flagrant example of this failure to instruct effectively.

     The whole-word approach to reading stresses the meaning of words over the meaning of letters, thinking

over decoding, developing a sight vocabulary of familiar words over developing the ability to unlock the

recommended by advocates of"open" classrooms and with the concept that children have to be developmentally

ready to begin reading. Before 1963, no major publisher put out anything but these"Run-Spot-Run" readers.

     However, in 1955, Rudolf Flesch touched off what has been called "the great debate" in beginning reading.

In his best-seller Why Johnny Can't Read, Flesch indicted(控诉)the nation's public schools for miseducating

students by using the look-say method. He said - and more scholarly studies by Jeane Chall and Rovert Dykstra

later confirmed - that another approach to beginning reading, founded on phonics, is far superior.

     Systematic phonics first teaches children to associate letters and letter combinations with sounds; it then

teaches them how to blend these sounds together to make words. Rather than building up a relatively limited

vocabulary of memorized words, it imparts a code by which the pronunciations of the vast majority of the

most common words in the English language can be learned. Phonics does not devalue the importance of

thinking about the meaning of words and sentences; it simply recognizes that decoding is the logical and

necessary first step.

1. The author indicts the look-say reading approach because ______.

A. it overlooks decoding

B. Rudolf Flesch agrees with him

C. he says it is boring

D. many schools continue to use this method

2. One major difference between the look-say method of learning reading and the phonics method is ______.

A. look-say is simpler

B. Phonics takes longer to learn

C. look-say is easier to teach

D. phonics gives readers access to far more words

3. The phrase "touch-off" (Para 3, Line 1) most probably means ______.

A. talk about shortly

B. start or cause

C. compare with

D. oppose

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