Choose the correct tense.When Sue __ back home, her sister __ the floor. came, had mopped had been coming mopped comes, did mop did come, had mopped

## Step 1<br />The problem is about choosing the correct tense for the sentence "When Sue back home, her sister the floor.". The sentence is in the past tense, so we need to choose the options that are also in the past tense.<br /><br />## Step 2<br />The first option "came, had mopped" is in the past tense. The verb "came" is the past tense of "come", and "had mopped" is the past perfect tense of "mop". This option correctly indicates that Sue's coming back happened after her sister had already mopped the floor.<br /><br />## Step 3<br />The second option "had been coming mopped" is not in the correct tense. The phrase "had been coming" is in the past perfect continuous tense, which is not appropriate for this context. The phrase "mopped" is in the past tense, but it doesn't make sense in this context.<br /><br />## Step 4<br />The third option "comes, did mop" is in the present tense. The verb "comes" is the present tense of "come", and "did mop" is the past tense of "mop". This option doesn't make sense in this context because it indicates that Sue's coming back happens after her sister mops the floor, not the correct order.<br /><br />## Step 5<br />The fourth option "did come, had mopped" is in the past tense. The verb "did come" is the past tense of "come", and "had mopped" is the past perfect tense of "mop". This option correctly indicates that Sue's coming back happened after her sister had already mopped the floor.