The [betydelsefulla] breakthrough on the polio front came with the Salk vaccine of the 1950s.

  • Type
    Text

Answers

  • major
  • key
  • important
  • decisive
  • crucial

You must be logged in to see the comments.

  • Rating
4.2

Rated by 29 users

All members (789)

Are you sure you want to delete this member?

 

Please wait...