Где начинается и где заканчивается пищевод? Какими тканями он образован? Почему пища в норме не попадает обратно в пищевод из желудка?

Пищевод начинается за глоткой и заканчивается в желудке. Он образован частично поперечно-полосатой, а частично гладкой мышечной тканью. Пища не попадает в пищевод из желудка потому, что на границе этих органов находится сфинктер, открывающийся только в конце акта глотания

№1

а) (-0,75; 2,75)

б) (0,1875; -5,25)

 

№2

б) n=2/3, m=1/3

в) z=3. y=-0.6

 

6m-9n=-4

2m+5n=4 / * -3

 

6m-9n=-4

-6m-15n=-12

способ сложения

 

-9n-15n=-4-12

-24n=-16

n=2/3

 

2m+5n=4

2m+5*2/3=4

m=1/3

 

 

б) 5y+8z=21  / * -2

      10y-3z=-15

 

    -10y-16z=-42

      10y-3z=-15

      способ сложения

 

      -16z-3z=-42-15

        -19z=-57

          z=3

 

      5y+8z=21

      5y+8*3=21

      5y=21-24

      5y=-3

      y=-0.6

 

 

 

1)  suddenly mr. bunting felt anything take hold of the back of his neck.

did mr. bunting suddenly feel anything take hold of the back of his neck?

did mr. bunting suddenly feel anything take hold of the back of his neck or his arms?

suddenly mr. bunting felt anything take hold of the back of his neck, didn't he?

who felt suddenly   anything take hold of the back of the neck?

what did mr. bunting feel?

 

2)  he was unable to lift his head.

was he unable to lift his head?

was he unable to lift his head or neck?

he was unable to lift his head, wasn't he?

who was unable to lift his head?

what was he unable to lift?

 

3)  mr.bunting looked at cuss, whose face had turned white with fear.

did mr.bunting look at cuss, whose face had turned white with fear?

did mr.bunting or mr.brown look at cuss, whose face had turned white with fear?

mr bunting looked at cuss, whose face had turned white with fear, didn't he?

who looked at cuss?

whom did mr.bunting look at?