X线机滤过板的作用是
A.降低皮肤剂量B.减小骨吸收量C.滤掉低能X线D.提高射线能量E.低射线能量
参考答案:C
根据课文内容,首字母填空:
Yesterday Lisa and her (1) p______ went to see Peking Man at Zhoukoudian near Beijing. The
(2) b______ of Peking Man were (3) f______ there .
Peking Man (4) l______ about 300,000 to 500,000 years ago. His head was like a (5) m______.
He was an ape-man. He lived in a big cave . He made things out of (6) s______. He used them to kill
animals for food. He (7) g______water from the river nearby. He made (8) f______ to cook and to
keep (9) w______ in winter .
Lisa and her parents (10) s______ some (11) d______ on the cave wall . They also saw some small
art work (12) m______ by Peking Man. Lisa (13) r______ enjoyed (14) v______ Peking Man's home.
一种衣服过去每件进价60元,卖掉后每件的毛利润是40元。现在这种衣服的进价降低,为了促销,商家将衣服八折出售,毛利润却比过去增加了30%,请问现在每件衣服进.价是多少元( )
A.28
B.32
C.40
D.48