为实现货币政策目标，中央银行可调控的中介指标有______。

A．利率

B．货币供应量

C．外汇配额

D．基础货币

E．超额准备金

In the following essay, each blank has four choices. Choose the most suitable one from the four choices and write down in the answer sheet. There are two types of key technology: private key and public key. Private-key encryption methods are called (71) ciphers, information is encrypted with (72) both the sender and receiver hold privately. Public-key encryption methods are called (73) ciphers, (74) created for each user, encryption key and decryption key are (75)

A．two related keys are

B．a key is

C．two unrelated keys are

D．three keys are