(a) That's why; (b) Only; (c) But/However; (d) Sometimes/Often; (e) Unfortunately; (f) As a result/Therefore; (g) So; (h) In fact/ Undoubtedly: (i) For example/For instance; (j) On the other hand/Meanwhile; (k) So/As a result/That's why; (l) Besides/ Moreover; (m) Therefore/Hence; (n) Otherwise

Time, by its very nature, is fleeting. (a)That's why , time once gone is gone forever. (b) Only the sincere people realize the value of time. (c) But/However not everyone is aware of the value of time. (d) Sometimes/Often it is seen that many of us waste time. (e) Unfortunately we realize the significance of lost time when it is too late. (f)  As a result/Therefore we suffer in life. (g) So all of us should make the best use of time. (h)  In fact/ Undoubtedly proper time management is the key to success in student life. (i)  For example/For instancewe find that an ideal student is the one who makes the best use of time. (j) On the other hand/Meanwhile ,a lazy student fails to make the grade as he kills time. (k) So/As a result/That's why the teachers advise their students not to waste time. (l) Besides/ Moreover they warn the students against their addiction to social networking sites and gaming. (m) Therefore/Hence students should follow the advice of their teachers. (n) Otherwise ,they will suffer in the long run.