综采设备螺纹连接件及紧固件的检修标准

题型:问答题 简答题

问题:

综采设备螺纹连接件及紧固件的检修标准

考点:综采维修钳工综采维修钳工(初级)综采维修钳工(初级)题库
题型:问答题 简答题

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.

On the whole, this passage is positioned to dwell on ().

A. the overall picture of the HDTV sector

B. how the giant TV makers should offer better products

C. a lament over consumers’ inability to use a high-end TV set

D. a criticism of the TV makers for doing nothing about a big problem

题型:问答题 简答题

1,25-(OH)2-D3的生理作用是()

A.升高血钙、血磷

B.降低血钙、血磷

C.升高血钙,降低血磷

D.升高血磷,降低血钙

E.不参与血钙、血磷浓度的调节

题型:问答题 简答题

治疗热入营分证的主方是()

A.清热地黄汤

B.白虎汤

C.清营汤

D.五味消毒饮

E.黄连解毒汤

题型:问答题 简答题

什么是细胞融合?细胞融合的方法有哪些?

题型:问答题 简答题

流体以层流掠过平板时,在x长度内的平均表面传热系数h与x处局部换热系数hx之比h:hx为()。

A.1:3

B.1:2

C.2:1

D.3:1

更多题库