如果电缆调制解调器使用4MHz的频带宽度，那么，在利用256QAM时，它可以提供的速率为 【20】 Mbps。
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具有益气健脾，清肺止咳，活血化瘀功效的药物是
A. 绞股蓝
B. 红景天
C. 刺五加
D. 灵芝
沙苑子的功效是
A. 补肾固精
B. 明目止泻
C. 两者均是
D. 两者均非
Who did Tom Smith write stories forFor ___________________________________.
Conversation 1
A. She had a high fever.
B. She was in good health.
C. She has caught a cold.
D. There is something wrong with her heart and lungs.
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