Unbelievable view appealed to me by accident．Just then, I checked once again: the somewhat tiny wood was having a leaf．Could I trust my own eyes? Had the hot sun annoyed me? After all, it as summer in Costa Rica, a country in Central America.
I left off, wiping sweat from my eyes．Then I moved the wood with my finger．It stopped．It looked up at me with big triangular eyes．Surprise! It was a mantid, a kind of insect, instead of a piece of wood．
The mantid was hanging upside down on a branch．Its wings made it look like a piece of tree bark．Then I noticed something else．The leaf wasn't a leaf at all．The hungry mantid was really eating another insect—a katydid．By now, all that was left of the katydid was a pair of wings．A few moments later, the wings dropped to the ground．The mantid folded its long legs．It sat still．Now it looked even more like a piece of wood than when I had first seen it．
I thought about how I had been fooled by these clever animals．Then I thought about how the two insects go about trying to trick each other．Both mantids and katydids are masters of make-up．Katydids are particularly good at it．Many look like something they are not．Katydids often look like plants．Many seem to be leaves．Others look like leaves of grass．All day, the bugs try to stay perfectly still．Because their bodies look like plants, most animals interested in killing them don't bother them while katydids eat plants．
What is the main topic of the text?
A．An experience of watching insects．
B．The fake image of mantids and katydids．
C．The fight between mantids and katydids．
D．The living habits of mantids and katydids．
What caused the author amazed at first?
A．The hot sun in summer．'
B．The quick moving of the wood．
C．The sight of wood eating a leaf．
D．The fight for food between mantids and katydids-
When the mantid was hanging upside down on a branch, it was ____．
A．waiting for its other food B．enjoying its food- katydid
C．eating a leaf from the branch D．having a break under the tree
Based on the passage, it can be inferred that the mantid ____．
A．is a kind of meat-eafer B．is easy to be found by a katydid
C．looks more like a green leaf D．mainly lives on the green leaves