Select the option that expresses the given sentence in the past tense. 'My grandparents walk in the park every morning.'

Identify the tense of the given sentence: 'The world has been infected with our ill-manners.'

Select the most appropriate option for the given blank. By the time you ______ my place, I will have left.

Select the most appropriate option to fill in the blank: 'Nisha ________ for her toy, which she misplaced last week.'