Consider the relations, containing information on names of authors, and who is authoring which papers, respectively: Authors(auID, name)and Authoring(articleID, authorID), the answer can be expressed in either SQL or algebra.
1. List the articles authored by John Smith
2. List the co-authors of John Smith (authors who co-authored an article with John Smith)
3. List the authors that have written no paper with John Smith
4. List the authors who have all their papers co-authored with John Smith
5. List the papers authored by only one author
6. which author co-authored at least 1 paper with every author (without aggregate functions)
7. List pairs (authorID and Name) of authors who have written at least one common paper

Your task this week is to write a very simple spam classifier in python. it will classify messages as either spam (unwanted) or ham (wanted). the program will have a set of spam_words, words that are known to appear in spam messages. that set is included in the template file spam.pypreview the document. you will also define a spam threshold which reflects the allowed percentage of spam words in the message. you'll compute a 'spam indicator', which is the ratio of spam words to the total number of unique words in the message. if the spam indicator exceeds the spam threshold, the message is classified as spam. otherwise it is classified as ham. we'll assume that the spam threshold is a constant and has a value of 0.10. your program will prompt the user for a message and then will print the corresponding spam indicator with two decimal digits and the corresponding classification (spam or ham). the program will be case insensitive. the spam words are detected whether they are in lower case or upper case or mixed case. each word, spam or not, is counted once (even if it appears multiple times in the message.) the program will remove punctuation from the message before identifying the words and computing the spam indicator. for example '! ' must be identified as the spam word 'now'.

Designing a mobile web page is a little different from designing a regular web page. name at least three features that should be considered when designing a website that is mobile phone-friendly, and briefly explain why they are important.

The head restraint should be adjusted so that it reaches a.the top of your ears b.the base of your skull c.the top of the head