We have a special part at this festival _____ every year. [ ]
A. /
B. in
C. on
D. at
答案:A
----_______is the radio station from here?
--- It’s about three kilometers.
A. How far B.How much C.How long
进行人群高血压普查时应选择的疾病频率测量指标是()
A.发病率
B.发病专率
C.罹患率
D.时点患病率
E.期间患病率