He is ________ to make money to help his parents live a better life.
A:old enough
B:enough old
C:young enough
D:enough young
如右图为不完整的人体细胞呼吸示意图,其中产生ATP最多的过程是 ( )
20世纪90年代,世界各大洲人口自然增长率最高的洲是