Questions 18 to 20 are based on the following passage.
At the end of the passage, you will be given 15 seconds to answer the
questions. Now listen to the passage. Which of the following expressions about "hand" is true
A．"To lend a hand" means to give up one’s hand. B．"To do it hands down" means the job is quite easy. C．"To wash one’s hands" means the hands are dirty. D．"To hand it to someone" means to give him help.