A:belonged to
B:are belonging to
C:are belonged to
D:belong to
I hope my parents can __________ me one day.
孝敬父母长辈是我们应尽的责任,这一责任主要来源于( )①法律 ②习俗 ③道德 ④承诺
下列关于静脉血的叙述,正确的是( )