4．What kind of story is most exciting？What story keeps you reading until the very end？The answer is the detective story．
Detective stories are among the most written，read and discussed stories in the world．They can be novels，animation and movies．When we start reading a detective story，we always wish to find out the truth before we reach the end．But it can be quite difficult to solve the problem as quickly as the detective does．（75）B the following elements （元素） may help you find the truth．
Motive
Your motive for doing something is your reason for doing it．Motive （动机） is the reason （76）A a crime．Some common motives are money，love，revenge （复仇） and so on．
Suspect
Suspects are those who may have done the crime．Usually there is （77）C one suspect in a case．Detectives have to find out the real criminal among them．Suspects with different genders （性别），ages，jobs and personalities often confuse the readers．
Clue
Clues （线索） are the most important things in solving a crime．Clues can be very （78）D things，such as hair，mud or a piece of paper from a diary．Clues don't lead directly to the truth．Detectives use reasoning to find out what those clues truly mean，and （79）A them together to find the truth．
Alibi
An alibi （不在场证明） is a special kind of evidence．It means a proof of your not being at the crime scene when the crime happened．For example，if you are having dinner with a friend when the crime happens，your friend's words are your alibi．（80）B，an alibi can be forged （伪造）．Your friend may have told a lie to protect you．
Detective stories are like puzzles．Following the elements of motive，suspect，alibi and clue can help us see what the detectives sees and solve the puzzle in the end．
| 75．A．Looking forward to | B．Paying attention to | C．Looking after | D．Getting rid of |
| 76．A．behind | B．beside | C．beyond | D．between |
| 77．A．only | B．about | C．more than | D．less than |
| 78．A．heavy | B．easy | C．dangerous | D．small |
| 79．A．put | B．leave | C．follow | D．start |
| 80．A．In addition | B．However | C．As a result | D．After all． |
