试述垄断性薪酬差别。

某人用手将1Kg物体由静止向上提起1m，这时物体的速度为2m/s，则下列说法正确的是（g=10m/s²）[ ]

A．手对物体做功12J

B．合外力做功2J

C．合外力做功12J

D．物体克服重力做功12J

第(6)题程序执行结束后，(DI)= 【7】 。

一种木料，用5种不同的工艺处理后研究缩小率试验。已知每种工艺做4次试验，并由测试结果计算得到方差分析表的主要结果如下表：

因子A的自由度（）。

A．fA＝5

B．fA＝4

C．fA＝15

D．fA＝20

下列药材不是寄生性植物的是（）

A.麦角

B.附子

C.槲寄生

D.桑寄生

A total of 4.6 million digital televisions have been sold, and the sales of HDTV sets have quadrupled since last year. Consumers have bought HDTVs to play their DVDs and to have clearer pictures and wide screens. Only a small percentage of the people who have purchased HDTVs, however, have actually ^hooked their TVs up# to receive high-definition television digital signals. Perhaps television viewers are having trouble keeping up with the changes in technology. Even the manufacturers of HDTVs, like Mitsubishi, Thomson Multimedia, Sony, and Samsung seem to have a tough time learning how to make their sets work with the various digital TV formats because little standardization has been required or implemented in the industry.Some of the HDTVs weigh over 200 lbs., and a variety of retailers offer a delivery service to the buyer’’s home to help install the heavy sets. This is known as a white-glove service and usually comes with an extra fee. After HDTV purchasers get their sets home and hook them up, they will still need to work to get the digital signals to their systems. Most of the industry’’s cable providers do not yet offer high-definition programing, and only about 15% of commercial television stations have switched over to even the lowest improved digital pictures. Worse yet, viewers may need to install antenna before they can even get the digital signals to their new HDTV sets. Another frustration for home-theater seekers is that the current HDTV sets allow owners only to watch high-definition programs, not to record them.

Hook up as in "hooked their TVs up" in Paragraph 1 most probably means to________.

A．have a hood over the TV

B．be connected to

C．relate oneself to

D．keep contact with