第6部分:完形填空(第51~65題,每題1分,共15分)
閱讀下面的短文,文中有15處空白,每處空白給出了4個選項,請根據短文的內容從4個選項中選擇1個最佳答案,涂在答題卡相應的位置上。
Less Is More
It sounds all wrong -- drilling holes in a piece of wood to make it more resistant to knocks.But it works because the energy from the blow gets distributed throughout the wood rather than focusing on one weak spot. The discovery should lead to more effective and lighter packaging materials. Carpenters have known____(51)____centuries that some woods are tougher than others. Hickory (山核桃木), for example, was turned into axe handles and cartwheel spokes(輪輻) because it can absorb shocks without breaking. White oak, for example, is much more easily damaged,____(52)____it is almost as dense. Julian Vincent at Bathe University and his team were convinced the wood's internal structure could explain the differences.
Many trees have tubular (管狀的) vessels that run____(53____)the trunk and carry water to the leaves. In oak they are large, and arranged in narrow bands, but in hickory they are smaller, and more evenly distributed. The researchers____(54)____this layout might distribute a blow's energy throughout the wood. soaking up a bigger hit. To test the idea, they drilled holes 0. 65 millimetres across into a block of spruce (云杉), a wood with____(55)____vessels, and found that (56)withstood a harder knock. ____( 57 )____when there were more than about 30 holes per square centimetre did the wood's performance drop off.
A uniform substance doesn't cope well with knocks because only a small proportion of the material is actually ____(58)____All the energy from the blow goes towards breaking the material in one or two places, but often the pieces left ____(59)____are pristine (未經破壞的).
But instead of the energy being concentrated in one place, the holes provide many weak spots that all absorb energy as they break, says Vincent. "You are controlling the places _
____(60)____the wood breaks, and it can then absorb more ____(61)____ , more safely. " The researchers believe the principle could be applied to any material -- ____(62)____example, to manufacture lighter and more protective packaging. It could ____(63)____ be used in car bumpers, crash barriers and armour for military vehicles, says Ulrike Wegst, a ____(64)____ at the Max Plank Institute for Mental Research in Stuttgart. But she emphasizes that you____ (65)____ to design the substance with the direction of force in mind. "The direction of loading is crucial," she says.
51.
A. in
B. since
C. for
D. at
52.
A. or
B. although
C. and
D. despite
53.
A. down
B. over
C. up
D. into
54.
A. knew
B. concluded
C. saw
D. thought
55.
A. no
B. per
C. each
D. every
56.
A. it
B. the idea
C. they
D. spruce
57.
A. if
B. Just
C. Only
D. Rarely
58.
A. knocked
B. beaten
C. slapped
D. affected
59.
A. behind
B. beyond
C. for
D. in
60.
A. which
B. there
C. that
D. where
61.
A. water
B. air
C. energy
D. safety
62.
A. among
B. in
C. as
D. for
63.
A. also
B. besides
C. else
D. yet
64.
A. psychologist
B. physicist
C. biologist
D. pianist
65.
A. have
B. must
C. should
D. had