空气中的氧气到达组织细胞所经历的过程是( )
①肺泡与血液的气体交换②组织细胞与血液的气体交换③肺与外界的气体交换④气体在血液中的运输.
A:③→①→②→④
B:③→①→④→②
C:③→④→①→②
D:③→④→②→①
Which of the following “ed” has a different pronunciation(发音) from the other three?