The 16 picked up the thermos and poured some hot water into the tea-cup and placed it on the small table in front of his 17 , who were a father and daughter, and put the lid on the cup with a clink．Apparently 18 of something, he hurried into the inner room, leaving the 19 on the table．His two guests heard a chest of drawers opening and a rustling （飒飒响声）．
They 20 sitting in the living-room, the 10-year-old daughter, looking at the flowers outside the window．The father was just about to take his cup when the 21 came, right there in the living-room．Something was hopelessly broken．
It was the thermos, which had fallen to the floor．The girl looked 22 her shoulder at once, startled （吓一跳）, 23 ．It was 24 neither of them had touched it, not even a little bit．
The sound caused the host to rush back from the inner room．He looked at the 25 floor and blurted out, “It doesn’t matter, it doesn’t matter!”
The father started to say something．Then he muttered, “Sorry, I 26 it and it fell．”
“ It doesn’t matter,” the host said．
Later, when they left the house, the daughter said, “ Daddy, I saw your 27 in the windowpane （窗玻璃）．You were sitting perfectly 28 ．Why did you say…．”
The father 29 , “What then would you 30 as the cause of its fall?”
“ It fell by itself．The floor is uneven （不平）．It wasn’t steady when Mr．Li put it there．”
“It won’t 31 , girl．It sounds more 32 when I say I knocked it down．There are things people accept less the more you 33 them．The truer your story is, the less true it sounds．”
The daughter was 34 in silence for a while．Then she said, “ Can you 35 it only this way?”
“Only this way,” the father said．
16．A．owner B．host C．guest D．master
17．A．friends B．neighbours C．children D．guests
18．A．knowing B．remembering C．hearing D．thinking
19．A．thermos B．cup C．lid D．tea
20．A．enjoyed B．remained C．imagined D．hated
21．A．stranger B．host C．crash D．noise
22．A．around B．at C．behind D．over
23．A．staring B．watching C．shouting D．crying
24．A．helpless B．exciting C．strange D．terrible
25．A．broken B．steaming C．dirty D．flooded
26．A．touched B．used C．hit D．moved
27．A．face B．shadow C．reflection D．action
28．A．calm B．still C．silent D．straight
29．A．shouted B．whispered C．laughed D．repeated
30．A．tell B．make C．accept D．give
31．A．do B．suit C．go D．fit
32．A．comfortable B．friendly C．acceptable D．agreeable
33．A．defend B．support C．discuss D．argue
34．A．kept B．shut C．worried D．lost
35．A．do B．explain C．make D．manage
g
g
g
，则
,按图乙装置在同一水平桌面上，设它们的共同加速度为a，得到
，联立解得a=
g，C对，ABD错。