They _________ the habit of visiting old friends,_________ I think is great.
A.keep on;which B.keep up;which
C.keep on;as D.keep up;as
They _________ the habit of visiting old friends,_________ I think is great.
A.keep on;which B.keep up;which
C.keep on;as D.keep up;as
B
keep on有继续之意,常用于keep on doing中,keep up是维持、保持的意思。本题是“保持习惯”的意思。which与as都可引导非限制性定语从句,但在从句中作主语时常用which,且as常有“正如……,像……一样”的意思。