本题目来源于试卷: SL/HL Topic B 3.2 Transport，类别为 IB生物学
[单选题]
1. Which of the following are involved is6stgwuss 9.r8 0o(ifdp)3km1sqzv0n the reah ie uq 0+puqpaa5ev 49mq8+- 04puihturn of blood to the heart in the e-ih8ev0i+m +4q 4uhpuapa puq5qa90 veins?
I. The pumping action of the heart.
II. Valves.
III. Skeletal muscle contraction.
IV. Peristalsis.
A. I only
B. II, III and IV only
C. II and III only
D. I, III and IV only
参考答案: C
本题详细解析:
暂无
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