hi iam egyptian i have aproblem with aqustion in english subject iam in the faculty of science
the qus is
please any body can help me

Read the following text then match the sentences below with their corresponding numbers that fit their meanings . each suitable sentence must be used once .

structural variations

All organisms, whether plant or animal, must reproduce, grow, breathe,
eat, excrete , and be able to respond to their environments; special areas of
animal’s bodies are often organized to accomplish each of these tasks . (…….1……) .
Differences in anatomy have arisen because , among other reasons , of the emergence of
life from the water onto land , which has meant that various features have had to be
modified to accommodate the exigencies of terrestrial life . (…….2……..) . It occurs
in all higher groups . even if only in the embryo stage .(…….3………).
The hydrostatic skeleton is asimple , fluid-filled cell and is found in animals such
as amebas . In higher invertebrates such as coelenterates , nematodes , annelids , and
echinoderms , water held inside the body is shifted by muscles to bring about a change in
shape or position of the animal . (……..4…….) . Muscles , which enable these
animals to move , are attached to the inside of the skeleton.
the main problem with this structural arrangement is that the exoskeleton is heavy
and eventually becomes too heavy for the internal muscles to lift . (…..5….) .
in contrast , vertebrates have an endoskeleton . which is an internal set of bony
supporting structures . (……..6……) . Each bone of the skeleton has muscles fixed to
its surface toward the end of the bones . (………….7…….) . The joints of the
vertebrate body are enclosed in a synovial capsule and are lubricated by synovial fluid .
(……..8……..) . (……..9……..) . The first increases in size until it
divides into two smaller individuals . Mammals , too , grow to an adult size at which time
they mature and become reproductively active , but they have special growth centers near
the tips of their long bones where the cell division that enables growth takes palce .
(……10……) .

* A.(…………..) But most invertebrates have an exoskeleton that is segmented and bears
jointed legs .
* B.(…………..) But one of the most important developments in the pattern of anatomical
organization is the occurrence of segmentation , first seen in the
earthwarm .
* C.(…………..) Consedering two extremes , amebas and mammals.
* D.(…………..) In addition , their skull bones are separated by cartilage which allows
the skull to grow – it stops the bones meet .
* E.(…………..) The backbone is strengthened by girdles to which limbs are attached .
* F.(…………..) The basic structure of an animal also determines how it will grow , and
the growth patterns of animals differ greatly.
* G.(…………..) These muscles work in antagonistic pairs , one contracting while the
other relaxes .
* H.(…………..) These specialized cells may vray from animal to animal , but the
chemical processes involved in the activity are usually the same .
* I.(…………..) Three basic support systems exist in the animal kingdom : a water-based
, or hydrostatic sdeleton ; a hard outer case ,or exoskeleton ; and
a hard internal support system , or endoskeleton .
* J.(…………..) This may be the reason for the small size of most invertebrates with
such astructure .