Structural stress levels in a ship are the sum of loading stresses and stresses due to（）.

A.connections between forebody and afterbody are most crucial
B.of maximum longitudinal bending moments
C.of severest racking stresses
D.resistance to grounding is at a maximum amidships

A.placing bunker on the deck
B.building a stage on which to place the cargo
C.welding steel feet to the deck，on which the cargo is placed
D.erecting vertical pillars under the deck to support the cargo