Question

1These books _________ very hard to understand
is
are
am
2Russia _________ one of the largest countries in the world
am
is
are

Answer 1

Vamos lá!!!

1) These books are very hard to understand:

Is

Are

Am

2) Russia is one of the largest countries in the world:

Am

Is

Are

Como usar o Verbo to be ?

You + are

I + am

He + is

She + is

It + is

They + are

We + are

You + are (plural)

Para coisas no singular use "is"

Para plural use "are"

BOOKS = plural

RUSSIA = singular

Outros exemplos:

She is here (she = ela = uma pessoa)

They are drinking coffee (they = eles / elas = plural/ um grupo de pessoas)

Espero ter ajudo:)