What does“a chocolate Lab" in Paragraph 2 refer to?

• A、 A scientist.
  
  

• B、A dog.
  
  

• C、A researcher.
  
  

• D、A cat.
  
  

60.(  )

According to the passage, which of the following reached the moo first?

• A、A pair of tortoises.
  
  

• B、American astronauts.
  
  

• C、Russian astronauts.
  
  

• D、Dogs and monkeys.