Suburani 07 Imperfect or Perfect?

Pick the best verb to complete the sentence:

ubi nōs (a)   , subitō clāmōrem​​ (b)   .

When we were talking, suddenly we heard a crash.

Pick the best verb to complete the sentence:

vōs flūmen trānsīre (a)   ; itaque mīlitēs pontem​ (b)   .

You kept wanting to cross the river; and so the soldiers built a bridge.​

Pick the best verb to complete the sentence:

canis celeriter ad pontem (a)   , quod dominus ibi​​ (b)   .

The dog quickly walked to the bridge, because his master was waiting there.

Pick the best verb to complete the sentence:

ego (a)   , quod mīles Rōmānus mē (b)   .

I kept shouting, because a Roman soldier wounded me.

Pick the best verb to complete the sentence:

cūr mē nōn (a)   , ubi pontem (b)   ?

Why did you not see me, when you were guarding the bridge?

Pick the best verb to complete the sentence:

ego librum nōn (a)   , quod tū (b)   .

I have not finished the book, because you kept talking.

Pick the best verb to complete the sentence:

nōs in Britanniā (a)   , sed nūper ad Italiam (b)   .

We used to live in Britain, but recently we sailed to Italy.

Pick the best verb to complete the sentence:

nautae multōs diēs (a)   , ubi ad īnsulam (b)   .

The sailors were sailing for many days, when they caught sight of an island.