下列哪种酶缺乏可引起蚕豆病？()
A. 内酯酶
B. 转酮基酶
C. 6-磷酸葡萄糖脱氢酶
D. 磷酸戊糖差向酶
The captain ______ this salvage contract as the representative of the owners of vessel and
A. writes down
B. enters into
C. takes note
D. works off
A vessel towing astern in an operation which severely restricts the towing vessel and her
A. the masthead lights for a towing vessel
B. the lights for a vessel restricted in its ability to maneuver
C. sidelights，stern light and towing light
D. All of the above
A vessel may use any sound or light signals to attract the attention of another vessel as
A. white lights are not used
B. red and green lights are not used
C. the signal cannot be mistaken for a signal authorized by the Rules
D. the vessel signals such intentions over the radiotelephone
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