【判断题】日常维护由维修企业进行,以检查、调整为中心内容 。
【单选题】You are about to cross a narrow channel. You see a vessel that can only be navigated safely within the channel. You should ______.
A.
not cross the channel if you might impede the other vessel
B.
cross the channel as you are the stand-on vessel
C.
sound the danger signal
D.
cross only if the vessel in the channel is approaching on your port side
【单选题】什么与肾功能损害程度呈正比,尤其对尿毒症的诊断很有价值。