Write the correct form of the verbs in brackets

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Write the correct form of the verbs in brackets.

Question 28: Twenty years ago, most people around the world __________ (not know) what the Internet was.

Question 29: In the future, robots _____________ (do) things that people can’t do or don’t want to do.

Question 30: My sister is really busy – she _____________ (study) for the exam.

Question 31: Children enjoy (ride) ___________________e-bikes to school ?