The astronauts are conducting a series of experiments to learn more about how the body ________ to weightlessness.

Gorillas and penguins are among the species most susceptible ________ ecotourism because they have a strong tendency to relax in the presence of humans.

Sarah thought the man was her buddy. He was walking down the street.

=> ____________________________________________________________.

Eric is really upset about losing his job.” – “Well, ________once myself, I can understand.”

Here is the assignment. You must finish it before going to the class.

=> Here is the ________________________________________________.

The man used to be a worker. He is sitting in an armchair.

=> __________________________________________________.