在病例对照研究中,选择偏倚主要包括
A.入院率偏倚B.奈曼偏倚C.检出征候偏倚D.时间效应偏倚E.以上均是
参考答案:E
The Canadian dollar has fallen about 20 percent in value, making that dream ski vacation in Whistler Mountains __________than ever.
A.seems more within reach
B.seem more within reach
C.seems within more reach
D.seem within more reach
为使所有的幻灯片设置统一的、特有的外观风格,应使用()。
A.母版
B.配色方案
C.自动版式
D.幻灯片切换