单项选择题
A．jump as high as you can B．slide down a rope to the ground C．attach yourself to a rope and fall to the ground D．fall towards the ground without a rope
33（）A．necessaryB．wonderfulC．importantD．harmful
单项选择题33（）
A．necessary B．wonderful C．important D．harmful
How do all food chains break（）A．One kind of animals is ...
单项选择题How do all food chains break（）
A．One kind of animals is eaten up. B．One kind of plants is destroyed. C．One kind of animals eats another. D．One of the links is destroyed.
How is food for plants made Food for plants is made （）A...
单项选择题How is food for plants made Food for plants is made （）
A．from water B．from the air in the sky C．from the soil D．from water, things in the soil and air and sunlight
