在(x-1)(x+1)8的展开式中x5的系数是[ ]
A.-14
B.14
C.-28
D.28
答案:B
弥漫性脂肪肝的声像图表现主要有()①肝脏增大;②回声增高密集;③远区回声衰减;④肝内血管模糊不清
A.①②③
B.①③
C.②④
D.④
E.①②③④
In any given year, the chance of a good year is 40 percent, an average year is 35 percent, and the chance of a bad year is 25 percent. What is the probability of having two good years in a row()
A. 16.00%.
B. 10.00%.
C. 8.75%.