The language system must constantly _______a new environment and situation to survive and flourish.[ ]

There was a lot of fun at yesterday’s party. You _____ have come, but why didn’t you? [ ]

Tim’s mum is worried _______ her son’seyesight as he plays online games too much.

Four dollars a pair? Ithink it’s a bit too much.-If you buy three pairs, the price for each will _______to three fifty.[ ]

From the next term, parents ______ e-mailsinstead of letters, to be informed of their children’sexam results.