某DNA分子有500个碱基对，其中含有鸟嘌呤300个，将该DNA进行连续复制，经测定最后一次复制消耗了周围环境中3200个含腺嘌呤的脱氧核苷酸，则该DNA分子共复制了多少次[ ]

A．3次

B．4次

C．5次

D．6次

Many young people in the West are expected to leave ______________ could be life’s most important decision — marriage — almost entirely up to luck.

A．as

B．that

C．which

D．what