根据当事人取得利益是否付出代价为标准，可以把合同分为( )。

A．要式合同与不要式合同

B．有名合同与无名合同

C．有偿合同与无偿合同

D．诺成合同与实践合同

The new hospital was        opened this morning，attracting the attention of all local media.

A．officially

B．automatically

C．directly

D．potentially