Почему вода и ветер не смывают всю почву?
Почему многие луга не зарастают лесом и не заболачиваются?
Как редуценты могут влиять на смену экосистем?
Что произойдет с экосистемой, если круговорот веществ в ней не будет полностью замкнутым?
Назови главные отличия искусственной экосистемы поля от природных экосистем.
В чем сходство природной и искусственной экосистем?
Приведи примеры быстрой смены экосистем.
Какие экосистемы наиболее устойчивы в твоей местности? Объясни, чем это обусловлено.
№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?