马吕斯定律
参考答案:
光线束在各向同性的均匀介质中传播时,始终保持着与波面的正交性,并且入射波面与出射波面对应点之间的光程均为定值。折、反射,费马原理及马吕斯定律可互推。
根据短文内容和以下提示:1)首字母提示,2)语境提示 3)汉语提示,在每个空格内填入一个适当的英语单词。所填单词要求意义正确,拼写准确。(10分)
The Sound of Music is one of the most p 小题1: American movies. It is a story
小题1:
a 小题2: a young woman living in Austria. 小题3: name was Maria. She went to Von Trapp family to 小题4: (照顾) for seven children.
小题2:
小题3:
小题4:
Mrs. Vop Trapp died , and the family were very 小题5: . The children cried and shouted every day. The father was 小题6: (孤独) and often became angry 小题7: the children were noisy.
小题5:
小题6:
小题7:
Maria 小题8: (教) the children to sing lively songs and perform short ,funny plays to
小题8:
c小题9: them up. The father was almost mad at 小题10: , but the smiling faces of his children made him happy again.
小题9:
小题10:
A.a为动滑轮,B端钢缆受到滑轮组的拉力大小约为3G
B.a为动滑轮,B端钢缆受到滑轮组的拉力大小约为G
C.a、c为动滑轮,B端钢缆受到滑轮组的拉力大小约为3G
D.a、c为动滑轮,B端钢缆受到滑轮组的拉力大小约为G