问题补充:
His grandparents at home on weekends.
A. are .all
B. are both
C. all are
D. both are.
答案:
A. are .all
(答案→)B. are both
C. all are
D. both are.
解析:all , both, 表示“都”,“全部”。 both指两个人或物,而all指三个以上的人或物,在句中都可作主语、宾语、表语、同位语或定语;both和all都可直接修饰名词;名词前如有限定词时,其前只能用both of或all of。both和all在句中的位置是位于be动词之后,行为动词之前,如有情态动词或助动词,则位于情态动词或助动词与主动词之间。句意:周末,他的爷爷奶奶都在家.结合语境可知选B.