已知：由静止开始做匀加速直线运动的物体在前4 s内的平均速度为10 m/s。求该物体在第4秒末的速度。
解：v0=0，(v0+v4)，即
Multipurpose Internet Mail Extension (MIME) is a (2) document messaging standard in the Internet enviroment, with MIME, users can send (3) Email messages that include audio, video, graph-ices, and text to any other user of a TCP/IP network. Richtext information can also be (4) into messages. It defines the fonts, formats, and (5) features of a document so the document can be easily (6) on many different types of systems.
A) incorporated B) filled C) stored D) flied
对我国的标准体制分析。 标准体制主要包括（）两方面内容。
A.标准分级
B.标准分类
C.标准性质
D.标准水平
(v0+v4)，即
(v0+v4)，即