单项选择题
The smallest size of flaw that can be detected on a radiograph examination of a weld will be indicated by the（）.
A.film speed B.penetrometer C.exposure reading D.time of exposure
单项选择题 The lines led forward from the bow and aft from the stern when a vessel is moored to the dock are（）.
单项选择题 The end of the joint with the exterior threads is called the（）.
单项选择题 The document on a vessel，annually endorsed by an American Bureau of Shipping surveyor，is called the（）.
