Halogens and Alkali react aggressively.
        
             
        
        
        
The research of astronomy during the time period of 1970 - 1990 is given below:
<u>Date</u>                                                   <u>Event</u>
1. 15 June 1974               Black Brant VC sounding rocket from White Sands.
2. 14 May 1973              Launch of Skylab, the USA's first space station
3. 26 July 1971          	Launch of Apollo 15
<h3>What is Astronomy?</h3>
This refers to the branch of science that deals with celestial bodies and their relation to each other.
Hence, from information about astronomy, between the time period 1970 - 1990 as it was on the 26th of December, 1974 that the Soviet space station Salyut-4 was launched.
The event I think had the greatest impact in astronomical history during this time period was the launch of Apollo 16.
Read more about astronomy here:
brainly.com/question/1141458
#SPJ1
 
        
             
        
        
        
We can only see things if they give off light but be we use other senses to gather information about things we cannot see.
 
        
             
        
        
        
Answer:
A. amount of precipitation, average temperature
Explanation:
Precipitation and average temperature are factors that climate includes. These factors are determined by other factors such as location of an area(like how far a place is from large bodies of water like the sea), ocean currents, lattitude (distance from the equator), winds (prevailing winds) , topography (such as mountains) and the like. 
 
        
             
        
        
        
Answer : 
B 
!!!!!!!!!!!!!!!