Fill in the blanks with words chosen from the box below. Change the form where necessary. 1) Some hard plastics are being used as____ for metals in manufacturing machine parts. 2) We must look at the problem in the right ________ if we are to make positive change in the way we do things. 3) If you get something without any efforts, you will not _______ it, and you will not feel the happiness. 4) Pigeons have a natural_______ to return home, even if they are very far away and the trip is hard or dangerous. 5) Even though she tries to hide her felinge, I can see she_______ pretty_______ by the letter. 6) While a man's clothing doesn't say anything about his intelligence, it says plenty about his ______, about his judgment, and about the opinion that he has of himself. 7) The fire which destroyed more than ten buildings ________ by the spark plug. 8) It is abolutely necessary for students to assimilate information and make the rignt decisions based on ______ thinking. 9) For some individuals, the______ to win at sports is greater than anything else, and some Olympic athletes are among them. 10) Having failed to carry out his promise to reduce employment which he made one year ago, the mayor is ______ with the biggest crisis of his political life.