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【单选题】
心室肌不发生强直收缩的原因是:A.
绝对不应期短
B.
有效不应期长
C.
有相对不应期
D.
有超常期
E.
有静息期
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皮皮学刷刷变学霸
举一反三
【单选题】----I am looking for information on social safety. ----You can take this book. Social safety is _______ introduced in it
A.
regularly
B.
naturally
C.
usually
D.
specially
【单选题】It can be inferred from the passage that apologizing properly is ______.
A.
a social issue calling for immediate attention
B.
not necessary among family members
C.
a sign of social progress
D.
not as simple as it seems
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