Problem: The abbreviation myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.6 teraseconds.

Myr is in common use where the term is often written, such as in Earth science and cosmology. Myr is seen with "mya", "million years ago". Together they make a reference system, one to a quantity, the other to a particular place in a year numbering system that is "time before the present".

Myr is deprecated in geology, but in astronomy "myr" is standard. Where "myr" "is" seen in geology it is usually "Myr" (a unit of mega-years). In astronomy it is usually "MYR" (million years).

In geology the debate of the millennia concerns the use of "myr" remains open concerning "the use of "Myr" plus "Mya"" versus "using "Mya" only". In either case the term "Ma" is used in geology literature conforming to ISO 31-1 (now ISO 80000-3) and NIST 811 recommended practices. Traditional style geology literature is written The "ago" is implied, so that any such year number "X Ma" between 66 and 145 is "Cretaceous", for good reason. But the counter argument is that having "myr" for a duration and "Mya" for an age mixes unit systems, and tempts capitalization errors: "million" need not be capitalized, but "mega" must be; "ma" would technically imply a "milliyear" (a thousandth of a year, or 8 hours). On this side of the debate, one avoids "myr" and simply adds "ago" explicitly (or adds "BP"), as in In this case, "79 Ma" means only a quantity of 79 million years, without the meaning of "79 million years ago".
1. is myr roughly the same as mya in amount?
2. what does mya stand for?
3. and myr?
4. how many teraseconds does it represent?
5. do they use it in astronomy?
6. how about in geology?
7. is there a debate between myr and mya usage?
8. which one is favored?
9. is myr avoided?
10. how do they do that?
11. which iso does ma conform to?
12. what NIST recommended practice does it conform to?
Answer: 1. yes
2. million years ago
3. million years
4. 31.6
5. yes
6. no
7. yes
8. the term "Ma"
9. yes
10. one avoids "myr" and simply adds "ago" explicitly
11. ISO 31-1 (now ISO 80000-3)
12. NIST 811

Problem: The region, as part of Lorraine, was part of the Holy Roman Empire, and then was gradually annexed by France in the 17th century, and formalized as one of the provinces of France. The Calvinist manufacturing republic of Mulhouse, known as Stadtrepublik Mulhausen, became a part of Alsace after a vote by its citizens on 4 January 1798. Alsace is frequently mentioned with and as part of Lorraine and the former duchy of Lorraine, since it was a vital part of the duchy, and later because German possession as the imperial province (Alsace-Lorraine, 18711918) was contested in the 19th and 20th centuries; France and Germany exchanged control of parts of Lorraine (including Alsace) four times in 75 years.

With the decline of the Roman Empire, Alsace became the territory of the Germanic Alemanni. The Alemanni were agricultural people, and their Germanic language formed the basis of modern-day dialects spoken along the Upper Rhine (Alsatian, Alemannian, Swabian, Swiss). Clovis and the Franks defeated the Alemanni during the 5th century AD, culminating with the Battle of Tolbiac, and Alsace became part of the Kingdom of Austrasia. Under Clovis' Merovingian successors the inhabitants were Christianized. Alsace remained under Frankish control until the Frankish realm, following the Oaths of Strasbourg of 842, was formally dissolved in 843 at the Treaty of Verdun; the grandsons of Charlemagne divided the realm into three parts. Alsace formed part of the Middle Francia, which was ruled by the youngest grandson Lothar I. Lothar died early in 855 and his realm was divided into three parts. The part known as Lotharingia, or Lorraine, was given to Lothar's son. The rest was shared between Lothar's brothers Charles the Bald (ruler of the West Frankish realm) and Louis the German (ruler of the East Frankish realm). The Kingdom of Lotharingia was short-lived, however, becoming the stem duchy of Lorraine in Eastern Francia after the Treaty of Ribemont in 880. Alsace was united with the other Alemanni east of the Rhine into the stem duchy of Swabia.
1. What Region was a part of the Holy Roman Empire?
2. Who annexed it?
3. when?
4. and what did it become?
5. What became of Mulhouse?
6. how?
7. by who?
8. when?
9. what had it been known as?
10. was Alsace part of Lorraine?
11. what was contested?
12. when?
13. How many times was control of Lorraine shifted?
14. between who?
15. over how many years?
Answer: 1. Lorraine
2. France
3. the 17th centuary
4. a trench province
5. b4ecame part of Alsace
6. a vote
7. it's citizens
8. 4 January 1798.
9. as part of Lorraine
10. yes
11. German possession
12. the 19th and 20th centuries;
13. Four
14. France and Germany
15. 75 years

Problem: Mary went to Canada on vacation. After a week, she came back to New York. She told lots of interesting things to her best friend, Jack. Jack was very interested in Canada and decided to have a visit there. The next summer vacation, Mary and Jack had a plan to go to Canada together. But her mother was badly ill so she went to the airport to see her friend off. When they got to the airport, Mary had to got to the washroom. When she came back, she couldn't find Jack because there were so many people at the airport. She looked for him everywhere, but it was hard to find Jack among the people. Suddenly Mary saw Jack and she felt very happy, so she shouted,"Hi, Jack. Here, here." At the same time, Jack waved his arms,"I'm here." In 3 minutes, so many policemen came to the front of Jack and caught him, "Please come with me to the police office." After the policemen found out the reason, they let them free. Why? Because the word "hijack" in the English has different meanings.
1. Who was detained by the police?
2. Who was he meeting at the airport?
3. Where was he travelling?
4. From where?
5. Who visited Canada first?
6. Was she going this time, as well?
7. Why not?
8. Why did she have difficulty locating Jack at the airport?
9. Was she relived to finally find him?
10. What did she yell?
11. What did the police think she said?
12. Was he taken to jail?
13. Where did they question him?
Answer:
1. Jack
2. Mary
3. Canada
4. New York
5. Mary
6. no
7. her mother ill
8. so many people
9. yes
10. Hi, Jack. Here, here
11. hijack
12. yes
13. the police office.