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【单选题】
如图所示555定时器,当 D=0时,555定时器的功能为()A.
直接
B.
翻转
C.
置1
D.
保持
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举一反三
【简答题】On the evening of 29th June,a day I shall never forget we landed at D.
【单选题】I shall never forget the look of intense anguish on the face of his parents when they heard the news.
A.
stress
B.
dilemma
C.
misery
D.
surprise
【单选题】However, the eruption itself is really exciting and I shall never forget my first sight of one.
A.
to watch
B.
to be watched
C.
watched
D.
watching
【单选题】下列属于条件反射的生理过程是
A.
伤害性刺激可引起肢体出现屈肌反应
B.
见到美味食品可引起唾液分泌
C.
低氧引起呼吸加深加快
D.
风沙入眼引起流泪
E.
瞳孔对光反射
【简答题】I shall never forget your kindness.
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