视网膜色素变性以________、________、________和________为特征
参考答案：夜盲；视野缩小；眼底骨细胞样色素沉着；光感受器功能不良
-- DO you still have a headache, Bill? -- No, it's _________. I'm all right now, mum.
A．dropped
B．run
C．left
D．gone
在哪些情况下应组织现场勘察？
