To find out whether bees can see colours, the following experiment is made. A table is put in a garden, and on the table is a blue card with some sugar on it. As soon as one bee finds the sugar, many more come to it one after another in a short time. It seems that one bee is able to tell the news of food to the other bees in their “ home”. After a moment, the blue card with sugar on it is taken away. Instead of this card, another blue card is now put on the left side of the first feeding place and a red card to its right. Nothing can be seen on the two cards. Very soon bees arrive again, and fly towards the blue card. No bees go to the red card.
(1)
How many cards are needed to make the experiment?
[ ]
A.
Two
B.
Three
C.
Four
D.
Five
(2)
During Step 3 of the experiment, the scientists put_____________.
[ ]
A.
a blue card with sugar on the left and a red card on the right
B.
a blue card in the middle, another blue card on its left and a red card on its right
C.
a blue card with nothing on it on the left and a red card on the right
D.
a blue card on the left and a red card with sugar on the right
(3)
During Step 3 of the experiment, the bees come to ____________.