
Photo credit: Paco CT via Foter.com / CC BY-NC-SA
HOT-AIR BALLOON => a lighter-than-air craft in which air heated by a flame is trapped in a large fabric bag. Hanging under the balloon, there is a basket (container) in which people can ride.
In this picture, you can notice that there are seven people in the basket and the flame is visible because they are flying:

Photo credit: Arun Katiyar via Foter.com / CC BY-SA
The first hot-air balloon was created in 1783 by two brothers, Joseph-Michel and Jacques-Ètienne Montgolfier.
CROWD => a large group of people. This is a crowd:

Photo credit: mararie via Foter.com / CC BY-SA
LAWN => grass-covered land.
In this picture, the lawn is dry, probably because it didn’t rain for a while (the grass isn’t green).

Photo credit: mugley via Foter.com / CC BY-NC-ND
STROLLER => a small carriage with four wheels that a baby or small child can ride in while someone pushes it.

Photo credit: alberth2 via Foter.com / CC BY-SA