死胎的定义是①妊娠≥20周胎儿在子宫内死亡②任何胎龄的胎儿死亡③体重≥ 500g的胎儿死亡④36周以后的胎儿死亡
A.①
B.②③
C.④
D.①②③④
E.②③④
参考答案:A
The Browns held _______ they called “family day” once each year.
A.that
B.what
C.which
D.when
量子种形成