02-10-36 请教两题文法题

请教两题文法题

1. _____over 100 years since the invention of the square-bottomed paper bag.

(A) Now is

(B) Now it has

(C) There is now

(D) It is now

答案是D, since不是要用完成式吗,那B改为Now it has been也对吗?

2. The oldest public edifice in Washington D.C., the White House was originally constructed in the 1790’s, also has been rebuilt or extensively remodeled three times since.

答案是C, also改为and吗??不懂它的考点为何

谢谢