The two diagrams illustrate the main parts of a hot air balloon and indicate how it ascends and descends in flight.

The 2 graphs depict the different parts of a

balloon

Use synonyms

and how it can ascend or descend during the flight.

Overall

Linking Words

,

it is clear that

Linking Words

to make the

balloon

Use synonyms

ascend, the

gas

Use synonyms

burners have to be on , in order to make the hot air go up in the

balloon

Use synonyms

's

envelope

Use synonyms

and the

valve

Use synonyms

has to be closed,

while

Linking Words

the

gas

Use synonyms

has to be off and the

valve

Use synonyms

has to be opened to let go the hot air to make the

balloon

Use synonyms

descend. The

balloon

Use synonyms

's ascent is made thanks to the

envelope

Use synonyms

which ends with a

valve

Use synonyms

, which has to be closed to make the

balloon

Use synonyms

go up.

In addition

Linking Words

, the

gas

Use synonyms

tanks, which are inside the basket for passengers, have to be

open

Wrong verb form

opened

show examples

in order to inflate the

balloon

Use synonyms

's

envelope

Use synonyms

. In opposition, the ballon's descent can be made thanks to the opening of the

valve

Use synonyms

situated on the top of the

envelope

Use synonyms

.

Then

Linking Words

, the

gas

Use synonyms

tanks have to be closed and the burners off to stop the hot air making.

Additionally

Linking Words

, the

valve

Use synonyms

of the

balloon

Use synonyms

has to be opened by the

valve

Use synonyms

cord activated by the pilot .