拿一个很小的方形孔,让太阳光垂直照射在方形孔上,那么地面上产生的光斑 [ ] A

题型:选择题

问题:

拿一个很小的方形孔,让太阳光垂直照射在方形孔上,那么地面上产生的光斑 [ ]

A.是方形的,它是太阳的虚像

B.是圆形的,它是太阳的虚像

C.是方形的,它是太阳的实像

D.是圆形的,它是太阳的实像

考点:光的直线传播的应用
题型:选择题

不符合肺心病的表现()。

A.胸片上可见Kerley-B线

B.P2>A2

C.肝大及双下肢水肿

D.胸片上可见肺动脉段突出

E.心浊音界左侧扩大

题型:选择题
A mother and her young son got on a bus and s     down. A girl, selling tickets on the bus, came to them. She was the conductor(售票员). The mother said,“I want a full ticket.” And t     she gave the conductor some m     . The conductor looked at the little boy and a     , “How old are you?” The mother wanted to speak, b      the conductor stopped h    , and the boy said, “I’m six years old at home, and four years old on b      and trains. My mother told me that.” The mother’s face turned r    . She had to take some more money o      of her bag and gave it to the conductor. The conductor gave her a full ticket and a half-price o     .
小题1:s
小题2:t
小题3:m
小题4:a
小题5:b
小题6:h
小题7:b
小题8:r
小题9:o
小题10:o
题型:选择题

袁世凯复辟帝制迅速败亡的根本原因是

A.护国运动迅速发展

B.帝国主义放弃对袁的支持

C.北洋军阀内部分化

D.卖国与复辟不得人心

题型:选择题

如图所示,在斜面顶端先后水平抛出同一小球,第一次小球落到斜面中点,第二次小球落到斜面底端,从抛出到落至斜面上(忽略空气阻力)

A.两次小球运动时间之比

B.两次小球运动时间之比

C.两次小球抛出时初速度之比

D.两次小球抛小时初速度之比

题型:选择题

本案中,对定金的处理方案应当是( )。

A.无线电厂收回全部定金

B.无线电厂可收回60%定金

C.电子公司取得全都定金

D.电子公司退回40%定金

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