Jack has ____ (been/fallen) ill for two weeks.
读黄河水系示意图,对各河段的描述,正确的是( )
图书馆有文艺书400本, ,有科技书多少本?
下列有关传染病和免疫的说法,正确的是( )
① The shoes are 20 yuan. ____ A.
② The shoes are 10 yuan. ____ B.
③ The skirt is nice. ____ C.
④ The shoes are expensive. ____ D.