下列树种哪些既可以作观果树种，其果实又可以食用（）。

A、草果，海棠果

B、开心果，南酸枣

C、苹果，薄壳山核桃

D、枇杷，杨梅

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• 临安东客食品的哪一款产品创新属于社会型创业的典型实践？

  A,蒲碳

  B,笋干

  C,山核桃肉

  D,茶叶

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• 共用题干Less Is More
  It sounds all wrong一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_________(1)centuries that some woods are tougher than
  others. Hickory (山核桃木）,for example, was turned into axe handles and cartwheel
  spokes（轮辐）because it can absorb shocks without breaking.White oak,for example,
  is much more easily damaged,_________(2)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（管的）vessels that run_________(3) 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_______(4)this
  layout might distribute a blow's energy throughout the wood,soaking up a bigger hit.To
  test the idea , they drilled holes 0._________(0.) 65 millimetres across into a block of spruce（云杉）,a
  wood with_________(5)vessels,and found that________(6)with stood a harder
  knock.__________(7)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_________(8).All the energy from the blow goes towards breaking
  the material in one or two places,but often the pieces left_________(9)are pristine（未
  经破坏的）.
  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_________(10)the wood breaks,and it can then absorb more__________(11),
  more safely."
  The researchers believe the principle could be applied to any material一______(12)
  example,to manufacture lighter and more protective packaging.It could__________(13)
  be used in car bumpers,crash barriers and armour for military vehicles,says Ulrike
  Wegst,_________(14)the Max Plank Institute for Mental Research in Stuttgart.But she
  emphasizes that you________(15)to design the substance with the direction of force in
  mind."The direction of loading is crucial,"she says. _________(15) A:have B:must C:should D:had

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