In William Roberts’ experiment, monkeys learned to take one date because they foresaw they would be ______ in the future.

A．The transportation for the trip is free.
B．The class won’t enjoy going on the field trip.
C．Some people may not go on the trip.
D．Everyone in the class has paid the fee.

A．Eliminating the original vegetation from the building site.
B．Making the houses in an area similar to one another.
C．Deciding where a house will be built.
D．Surrounding a building with wildflowers and plants.