我国的内海是[ ]
A、渤海和南海
B、南海和东海
C、东海和黄海
D、渤海和琼州海峡
答案：D
_________ their final medical check, the astronauts boarded their spacecraft.
A．Received
B．Being received
C．To receive
D．Having received
关于药物经济学中的成本
因诊断治疗过程中带来的担忧、痛苦属于
A．成本B．直接成本C．间接成本D．隐性成本E．以上均不是
