Question

Escreva there was ou there were
A rose in the vase.
Roses in the base
A boy in the street
A yellow house
Birds on the wire.

Answer 1

Escreva there was ou there were

There is A rose in the vase.

There are Roses in the base  

There is A boy in the street

There is A yellow house

There are Birds on the wire.

simples, quando for singular você usa THERE IS, quando for plural você usa THERE ARE...

A rose (a rosa)

Roses (rosas)

A boy (o garoto)

A yellow (a amarela)

Birds (passaros)

Answer 2

There was a rose in the vase. (Singular)
There were roseS in the base.(plural)
There was a boy in the street. (Singular)
There was a yellow house. (Singular)
There were birdS on the wire. (Plural)
Se for mais que um (were) se for um (was)