Some of the world’s best mountain scenery __ available near the Southern Alps.
A. is
B. are
C. maybe
D. has been
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Sometimes even the smallest thing will upset an __ person.
A. annoyed
B. irritated
C. irritable
D. angry
Bob Geldef and his friends did all that they could ______ the poor in Africa.A) help C) helpingB) to help D) be helped
A. Bob Geldef and his friends did all that they could ______ the poor in Africa.
B. help
C. to help
D. helping
E. be helped
与心室肌细胞相比，浦肯野细胞动作电位的主要特征是
A. 平台期时程长
B. 幅值大
C. 4期膜电位稳定
D. 4期自动去极
E. 0期除极速度快
呼吸衰竭通常是指
A. 外呼吸功能严重障碍
B. 内呼吸功能障碍
C. 血液运输氧障碍
D. 二氧化碳排出功能障碍
E. 呼吸系统病变造成吸入氧减少
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