电子天平显示“-E”时,主板有故障的修理方法是()
A、检修主板故障
B、安装秤盘并保证安装良好
C、正确调整电子天平的预载荷
D、排除称量系统卡碰之故障
参考答案:A
口语应用,根据句意填入适当的句子,词组或单词完成对话。
A: Where is Lucy?
B: 1. to English.
A: 2.___________________________?
B: Yes. She has been there once.
A: 3.___________________________?
B: She went there last week.
A: 4.___________________________?
B: She is going to stay there for a month.
A: Do you know 5.___________________________?
B: She'll be back at the end of October.
下列选项中HIV感染的高危人群有()
A.同性恋者
B.性乱交者
C.静脉吸毒者
D.医务工作者
E.住同一宿舍者