除当事人另有约定外，保管合同的成立时间为（）。

［A］ one of NASA’s internet projects

［B］ an expedition to Mars

［C］ the infrastructure of the interplanetary Internet

［D］ to create an architecture on Mars

［A］ Sony: The Private Life is the biography of Akio Morita

［B］ Sony’s Japanese leaders have been too practical-minded

［C］ this management problem of Sony cannot be rectified overnight

［D］ Nathan did not write about how Sony established itself as the electronics giant

［A］ The development of the Internet.

［B］ The possibility of space research.

［C］ Universal information superhighway.

［D］ The technological advances of the Mars mission

A．价值形式划分的

B．交换形式划分的

C．补偿形式划分的

D．实物形式划分的