3道题目，请NN解答，不胜感激！！

Q1: The sale of government surplus machinery will begin at 9 a.m and continue until the supply lasts.

E) will begin at 9 a.m and continue as long a the supply lasts

为什么不能用until

Q2:

 For many people, household labor remains demanding even if able to afford household appliances their grandparents would find a miracle.
(A) even if able to afford household appliances their grandparents would find a miracle
(B) despite being able to afford household appliances their grandparents would find a miracle
(C) even if they can afford household appliances their grandparents would have found miraculous
(D) although they could afford household appliances their grandparents would find miraculous
(E) even if they are able to afford household appliances which would have been a miracle to their grandparents

为什么选C,其他的选项错在哪里？？？

Q3:

In the traditional Japanese household, most clothing could be packed flatly, and so it was not necessary to have elaborate closet facilities.
(A) flatly, and so it was not necessary to have elaborate closet facilities
(B) flat, and so elaborate closet facilities were unnecessary
(C) flatly, and so there was no necessity for elaborate closet facilities
(D) flat, there being no necessity for elaborate closet facilities
(E) flatly, as no elaborate closet facilities were necessary

选B，请问其余各项错在哪里？？？

实在不懂，再追加一题，请赐教！！

At the time of the Mexican agrarian revolution, the most radical faction , that of Zapata and his followers, proposed a return to communal ownership of land, to what had been a pre-Columbian form of ownership respected by the Spaniards. (Z.P. 129)

  A) land, to what had been a pre-Columbian form of ownership respected by the Spaniards

  B) land, a form of ownership of the pre-Columbians and respected by the Span iards.

  C) Land, respected by the Spaniards and a pre-Columbian form of ownership

  D) Land in which a pre-Columbian form of ownership was respected by the Span iards

  E) Land that had been a pre-Columbian form of ownership respected by the Spa niards

为什么选A,其他的错在哪里