已知区域Ω={(x,y) |x+y≤10,x≥0,y≥0},A={(x,y)|x-y≥0,x≤5,y≥0},若向区域Ω随机投1个点,则这个点落入区域A的概率P(A)=( )。
颌面部放疗引起放射性颌骨坏死的照射剂量最小为()
A.3OGy
B.4OGy
C.5OGy
D.6OGy
E.7OGy
---What does Old Walter usually do in his retirement?
---- These days he is ______ memories of village life for his new book.
A.putting up
B.putting on
C.setting up
D.setting down