Which three statements about end-to-end delay are true？（） ["End-to-end delay is the sum of propagation delays，processing delays，serialization delays，and queuing delays.","Coast-to-coast end-to-end delay over an optical link is about 20 ms.","Processing delay depends on various factors，which include CPU speed，CPU utilization，IP switching mode， and router architecture.","Propagation and serialization delays are related to the media.","Propagation delay is the time it takes to transmit a packet and is measured in bits-per-second （bps）.","Serialization delay is the time it takes for a router to take the packet from an input interface and put it into the output queue of the output interface."]
同一基因型不因环境条件改变而产生不同表型。
公司在工商行政管理部门登记注册的资本即所谓注册资本。（）
有氧耐力运动对大众健身特别有益，要提高健身效果，必须保证（） ["心率大约140~170次／分，持续时间40~60分钟，每周锻炼频率3~4次","心率大约120~160次／分，持续时间30~50分钟，每周锻炼频率2~3次","心率大约140~170次／分，持续时间40~60分钟，每周锻炼频率2~3次","心率大约120~160次／分，持续时间40~60分钟，每周锻炼频率3~4次"]
合作学习的要素包括（）。 ["积极互赖","个体责任","面对面的积极互动","社交技能","小组加工"]
效应
