( )16. Why did the stream in Pinegrove Forest dry up?
B
( )17. Who said “Let’s follow the dry stream”?
B
( )18. What happened after they moved the tree?
B
( )19. What lesson did the animals learn?
C
( )20. What did the animals promise to do?
A
答案：B B B C A
情景问答
请看下面的情景提示：
海洋覆盖了地球表面约71%的面积,并且生产了地球上约70%的氧气。
(1)____
(2)____
答案：1.71%.
2.70%.
