网络互联设备通常分成以下四种,在不同的网络间存储并转发分组,必要是可以通过_________进行网络层下协议转换。
You can _____ some bottles of wine, or some chocolates, or a bunch of flowers.
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
免费的网站请分享给朋友吧