SAT OG 1.（Until being widely hunted for its） ivory and blubb

SAT OG
1.（Until being widely hunted for its） ivory and blubber in the eighteenth century ,walruses were plentiful in the waters of the northeastern United States.
D Until they were widely hunted for their
E Before they have been widely hunted for their
为何选D不选E
2.Persuading even the queasiest of readers to spend hours learning about an extravagant variety of invertebrates,（the effect of Richard Conniff's Spineless Wonders is to render the repulsive beautiful.）
B Richard Conniff's renders the repulsive beautiful in Spineless Wonders
E Spineless Wonders ,by Richard Conniff,has effect in rendering the repulsive beautiful
为何选B不选E