4. A。词义猜测题。上文提到对十五人进行研究表明在整个航行过程中骨损在继续,下文再说especially striking,可知是“特别明显”的事,因此选A。
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Some
spiders hunt on the ground, others build webs to trap their food, but the grass
water spider catches its prey by running along the surface of the water.
This
special water spider lives on the grassy banks of streams where mosquitoes,
damsel flies and other insects come to feed and breed.
Although
it is one of the largest spiders in New Zealand, it has an unusual ability. It
doesn’t disturb the water as it waits for its meal, and there is barely a
ripple(波纹) when it skims(掠过) across the surface at lightning speed
to catch its prey.
Grass
water spiders deal swiftly with larger insects like damsel flies by pulling
their heads under the water and holding them there until they drown.
After
a meal, the grass water spider spends up to half an hour grooming(修饰) itself. It wipes its eight eyes,
brushes its antennae(触角), and takes special care to
clean the hairs on its body.
It is
the hairs that trap tiny bubbles(泡沫)
of air so that the spider can run down a blade(叶片)
of grass and stay underwater for up to an hour when it is frightened. The hairs
also keep the spider dry, even underwater.
It is
only when the female spider is caring for the young that she does not hunt on
the water. After mating, she produces a large egg sac(囊), which she carries around for five
weeks. Once the eggs start to hatch, she attaches the sac to some blades of
grass or a thistle. She then tears the sac open and releases the tiny spiders
into the nursery web.