生态系统中,能量从一个营养级向另一个营养级传递时的效率大约是 ( )
A.10%~20%
B.30%~40%
C.0.1%~1.0%
D.1%~2%
参考答案:A
There is no such place ________ you dream of in all this world.
A.that
B.what
C.which
D.as
加拿大人均能源消耗量比美国人均能源消耗量多( )。
A.3.0%
B.3.1%
C.3.2%
D.3.3%