1. Words adoptive = to become parent of a child that isn't your own claim

essential = very important and necessary

even though = true, but other things are true too

limit = control, check

measure = to find out how big something is

molecule = smallest unit made up of two or more atoms

observe = watch closely

protect = to keep something safe

recover = to return to a normal condition

release = set free

responsible = the reason for

scientist= person who is trained in science and works in a lab

sign = put your name on a document

state = say in public

substances = elements; material

take effect = start

ultraviolet radiation= light that comes from the sun but cannot be seen; it makes your skin darker

welcome = to be glad that something has happened


20.

Words

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  British-based = its main headquarters are in the U.K.
  
• 
  discover = to find for the first time
  
• 
  colourless = clear, so that you can see through it
  
• 
  Crown Jewels = objects that are a symbol of the British monarchy, kept in the Tower of London
  
• 
  especially = above all
  
• 
  gem = beautiful stone that has been cut into a special shape
  
• 
  government = people who rule a country
  
• 
  grave = serious, bad
  
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  impurity = object that is not very pure; with other substances that are mixed into it
  
• 
  including = also
  
• 
  landlocked = country that has no coast
  
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