1、perpetual 

continuing forever or indefinitely

He has run his course and taken his perpetual rest.

eternal 

A wedding ring is a symbol of eternal love between a married couple.

2、empirical

deprived from experiment and observation than theory.

relying on medical quackery.

He is involved in an empirical study.

3、logical

capable of thinking and expressing your self in a clear and consistent manner.

Mathematics requires logical thinking.

4、comet

(astronomy) a relatively small extraterrestrial body consisting of a frozen mass that travels around the sun in a highly elliptical orbit.

Did you ever see a comet?

5、speculative

not financially safe or secure.

not based on fact or investigation.

showing curiosity.

I would not make any comment on speculative reports that are completely baseless.

6、compelling

driving or forcing.

tending to persuade by forcefulness of argument.

Her latest book makes compelling reading.

7、propose

present for consideration,examination,criticism,etc. .

He proposed another meeting.

8、alpha

first in order of importance

early testing stage of a software or hardware product

The researches are concerned with alpha rays.

9、disprove

prove to be false

In his latest book, he writes that the theory has been disproved.

10、artillery

an army unit that uses big guns

The invaders would also has artillery.

11、apparatus

equipment designed to serve a specific function

The demonstrators set up apparatus for the experiment.

12、atom

(physics and chemistry) the smallest component of an element having the chemical properties of the element

Water is made up of atoms of hydrogen and oxygen.

13、eclipse

one celestial body obscures another

It will take an hour to reach full eclipse stage.

14、magnificent

characterized by grandeur

It was magnificent of you.

15、ingenious

showing inventiveness and skill

I never heard anything more ingenious than your suggestion.

16、heavenly

relating to or inhabiting a divine heaven

The sun, moon and stars are heavenly bodies.

We spent a heavenly day at the beach.

17、Islamic

of or relating to or supporting Islamism

This book introduces many Islamic commandments.

18、monopoly

(economics) a market in which there are many buyers but only one seller

exclusive control or possession of something

a board game in which players try to gain a monopoly on real estate as pieces advance around the board according to the throw of a die

Liberty and monopoly cannot live together.

19、quash

put down by force or intimidation

declare invalid

The army was called in to quash the revolt.

20、chromosome

a threadlike strand of DNA in the cell nucleus that carries the genes in a linear order

Chromosome breaks may also lead to inversions.