硬膜外麻醉时下述哪些必须处于良好的备用状态（）
A.麻醉机
B.氧气
C.喉镜
D.合适的气管导管及面罩
E.麻黄碱
参考答案：A, B, C, D, E
精神病患者所立遗嘱，不管是发病前所立还是发病后所立都不具备法律效力。
根据句意和汉语注释，写出单词的正确形式。
1. Tim's brother is so _____ (care) that he often forgets to do his homework.
2. Those _____ (visit) will stay in our school for two days.
3. It's very important for us to keep _____ (save).
4. They were too tired to walk any _____ (far).
5. Mary can learn Japanese by _____ (she).
