When buyer and seller discuss the terms of the contract，terms of shipment are (1) ．Terms of shipment include methods of transport，time for shipment，partial shipment and transshipment，port or place of loading and unloading， (2) ，etc．when the traders discuss the time of shipment in the contract，they should take the following into account：The (3) should consider whether he can get the goods ready before the shipment date and whether the ship is available if the goods are ready．The time of shipment should be stipulated in a clear and (4) way．Sometimes，the L/C simply stipulates an expiry date without a shipment date，which means these two dates are (5) ．
A．importance
B．necessity
C．compulsory
D．major