Exercise 1: Insert the correct form of the word in brackets into each blank below.

NOTE THAT YOU WILL NEED TO USE PREFIXES on some of the words.

1. By 1860 Biela's comet___________________ and, in its place, there is an annual meteor shower of the debris. (appear)

2. Six spaceships flew out in_______________________ to investigate Halley's comet. (form)

3. It is not _______________________known if extra solar comets enter the Oort cloud. (define)

4. The ___________________ of the comet's nucleus is not yet known; Greenberg believes that it has a structure. (compose)

5. A periodic comet's return can ____________ (predict)

6. _______________ is another term for material in a gaseous phase. (vaporize)

7. There is a cloud of gas ______________________ the comet's nucleus. (surround)

8. The ____________________ that the universe originated with a "Big Bang" is currently accepted by most cosmologists. (theorize)

9. There may be a ____________________ between "dead comets" and asteroids. (link)

10. It takes thousands of years for some plastics in a land-fill they should be recycled. (compose)

11. Scientists provide formal for the concepts that they use. (define)

12. The shekel value and that of other currencies to that of the dollar. (line)

13. An irrational person's behavior is (predict)

14. The one lives in affects one's moods. (surround)

15. _____________ is the process in which a substance becomes a gas or evaporates. (vaporize)

16. Some disciplines no longer have clearly boundaries; the lines are blurred. (define)

Exercise 2: formal definitions

Insert the missing parts (articles, categories, differentiators, verbs) of each formal definition below.

Remember, often there are several categories and differentiators which can be used in a formal definition. These are suggestions.

1. MARS is _________ ________________ in the inner solar system which is fourth in distance from the Sun.

2. Gravity assists are __ which utilizes a planet's energy and motion to increase a satellite's velocity or change its trajectory.

3. Hibernation is a condition in which an animal or object______ _________

____________________________________________________________________ .

4. __________ Lander is a part of the Rosetta spacecraft which

___________________________________________ .

5. Monitoring is a __ in which a person, object, or activity is _______

_________________________________________________________________________.

6. 46P/Wirtanen is a periodic comet which _________________ and __________________________________________________________________________.

7. Consortia are ________________________________________________ which cooperate

for a common purpose or goal.

8. ___________________________ solar wind is the continuous ejection of charged particles from the Sun's corona which _______________________________________________

9. ________________ Rosetta stone is a _____________ which contains information in three languages and was used to translate Egyptian heiroglyphics.

10. Darmstadt is a ________________ from which the ESA's Rosetta Mission will be monitored.

Laser