实行持仓限额制度的目的在于防范操纵市场价格的行为和防止期货市场风险过度集中于少数投资者。()
参考答案:对
--- Excuse me, have you seen _______ umbrella here?
--- Yes. Is it _______ beautiful blue one? I saw it here just now.
A.an, the
B.an, a
C.the, the
D.the, a
心动周期指的是()。
A.心房收缩和舒张一次
B.心室收缩和舒张一次
C.心房或心室每舒张一次
D.心房和心室每收缩和舒张一次
E.心脏收缩一次