什么叫标识符？VHDL的基本标识符是怎样规定的？_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题问答题简答题

什么叫标识符？VHDL的基本标识符是怎样规定的？

答案

参考答案：

标识符是指用来为常数、变量、信号、端口、子程序或者参数等命名，由英文字母、数字和下划线组成。

遵从的规则：

（1）首字符必须是英文字母。

（2）不连续使用下划线“_”，不以下划线“_”结尾的。

（3）大小写英文字母等效，可以大小写混合输入。

（4）标识符中不能有空格。

（5）VHDL的保留字不能用于作为标识符使用。

完形填空

On August 26, 1999, New York City was struck by a terrible rainstorm. The rain caused the streets to   36  and the subway system almost came to a stop.
Unfortunately, this happened during the morning rush hour. Many people who were going to work were   37 to go home. Some battled to   38  a taxi or to get on a bus. Still others faced the   39   bravely, walking miles to get to work.
I   40 to be one of people on the way to work that morning. I went from subway line to subway line only to find that most   41   had stopped. After making my way   42   crowds of people, I finally found a subway line that was   43.            Unfortunately, there were so many people waiting to   44 the subway that I could not even get down the stairs to the   45 . So I took the train going in the opposite direction, and then switched back to the downtown train.
Finally, after what seemed like forever, the train   46    my stop. Then I had to walk several blocks in the increasingly heavy rain. When I finally got to my office, I was 47 through, exhausted and   48 .
My co-workers and I spent most of the day drying off. When it was 5:00 pm, I was ready to go home. I was about to turn off my computer   49 I received an email from Garth, my Director:
I would like to thank all of you who made the effort and   50   went to work. It is always reassuring(令人欣慰), at times like these, when employees so clearly show their   51   to their jobs. Thank you.
Garth’s email was short, but I learned more from that   52   message than I ever did from a textbook. The email taught me that a few words of   53   can make a big difference. The rainstorm and the traffic 54 had made me tired and upset. But Garth’s words immediately   55   me and put a smile back on my face.

B．discouraged

B．appreciation

单项选择题

关于独立董事的选任，下列说法正确的是( )。

A．独立董事可以由上市公司董事会提名

B．独立董事应当经上市公司董事会选举产生

C．独立董事任期届满可以连选连任，连任时间不得超过8年

D．独立董事应当由董事会解任