【判断题】In a standard format of business email, it is not necessary for us to begin with date according to the video.
【单选题】In a standard format of business email,s we are not necessary to begin with ___ according to the video.
【单选题】In a standard format of business email, we don’t necessary to begin with ___ according to the video.
【简答题】抓钩本身为一带有()的链板,作为板链中的—个链环,根据钩状物的位置,抓钩可 分成()和()两种。
【单选题】纵断面设计图上的设计线是由坡度线和( )构成。