單項(xiàng)選擇題
A.1次/天B.2次/周C.1次/周D.1次/2周
A.高、中、低三個(gè)劑量組,陰性對(duì)照和陽性對(duì)照組B.高、低兩個(gè)劑量組,陰性對(duì)照和陽性對(duì)照組C.高、中、低三個(gè)劑量組,陰性對(duì)照D.高、中、低三個(gè)劑量組,陽性對(duì)照組