A.隊(duì)列研究 B.病例對(duì)照研究 C.生態(tài)學(xué)研究 D.社區(qū)實(shí)驗(yàn) E.現(xiàn)場(chǎng)實(shí)驗(yàn)
A.1.0% B.61.4% C.30.2% D.1.3% E.0.4%
A.1.8 B.2.6 C.0.6 D.0.4 E.1.4