常用的封管液都有哪些?
参考答案:
①无菌生理盐水,每次用5~10ml,每隔6~8小时重复冲管一次。②稀释肝素溶液,每毫升生理盐水含肝素0~100U,每次用量2~5ml。
According to the speaker, it is foolish and childish for a filmmaker to mix his preconceptions with objective truth when he produces a documentary.
目前公用电话网广泛使用的交换方式为()
A、电路交换
B、分组交换
C、数据报交换
D、报文交换