阅读理解
Frogs are animals that can live both in water and on land．There are more than 5.000 kinds of frogs on the earth．The earliest known frogs lived about 190 million years ago and the frogs today still look the same．Here are some fun things that you might not know about frogs．Enjoy！
The Biggest and the Smallest Frogs
Some frogs can be very big．The biggest kind of frog is the Goliath Frog in West Africa．Its body can be nearly 30cm long，about the size of a large cat．The Gold Frog and the Poison Frog are the smallest frogs in the world．They are less than lem long．Though the Poison Frog is very small，it is not weak at all．It is dangerous．Any animal that eats it will die very soon．
The Best Jumpers
Frogs are very good at jumping．They developed jumping legs so that they would not be eaten by other large animals．Using their big strong legs，most frogs can jump over 20 times their own length．It is like a person jumping over about 30.48m．The Australian Rocket Frog can even jump over 2m，which is 50 times its body length（5.5cm）．That might be the reason why frogs are called the best jumpers on the earth．
The Cryogenic Animal
Some frogs like the Common Wood Frog have a special ability to live in very cold places．When the temperature goes down，they become ice frogs．2／3 of their body water freezes．Their hearts stop，and their breathing stops too．You may think they are dead，but in fact they are not．Maybe we humanscan learn thc way that the frogs do for medical purpose．
The earliest frogs lived about________million years ago．

A．20

B．30

C．50

D．190

The Gold Frog is one of the________frogs on the earth．

A．smallest

B．biggest

C．strongest

D．weakest

________can jump over 2m．

A．The Goliath Frog

B．The Common Wood Frog

C．The Poison Frog

D．The Austrailan Rocket Frog

What will happen to a Common Wood Frog at very low temperatures？

A．It will die very soon．

B．It will be an ice frog．

C．It will become dangerous．

D．It will become very small．