Good harvest this year has made it possible for us to supply walnuts ______ last year's prices.

A. at

B. in

C. against
D. on

Windows开机，下列叙述正确的是（）。

A.所有程序都会自动启动

B.登录windows前先要进行系统自检

C.每次进入Windows都需要调整时间

D.登录windows系统都不需要输入登录密码