【单选题】— I will be right back in an hour. Will you wait for me? — I'm afraid not. He probably have gone to a meeting ______ then.
【判断题】彩色合成水晶一般是将自然界中有色的或无色的石英晶体经过热处理或辐射热处理而获得的。
【单选题】— I wonder if you can go shopping with me together. — Sorry. I _____ a letter all the morning and haven't finished it yet. [ ]
【单选题】根据卫生部相关规定,当前独立从事家庭访视护理的护士,应具有在医疗机构从事临床护理工作的经验至少