[原创]问两个OG上的语法题

一个是33题

Because an oversupply of computer chips has sent prices plunging, the manufacturer has announced that it will cut production by closing its factories for two days a month.

A.    Because an oversupply of computer chips has sent prices plunging,

B.    Due to plunging computer chip prices from an oversupply,

答案是A,但想不通为什么B错了

Dressed as a man and using the name Robert Shurtleff, Deborah Sampson, the first woman to draw a soldier’s pension, joined the Continental Army in 1782 at the age of 22, was injured three times, and was discharged in 1783 because she had become too ill to serve.

答案说这句话是对的，但为什么joined前不加who，或者把joined改成joining,要不不是有joined, was injured两个谓语么？或者因为Joined the …是个插入语，不计？

谢谢大家帮助~~