75. Police officer don’t have to wear uniform when they are …………….. duty.
A on                    B in                          C of                   D off
  76. Hue will have temperatures……………  23 degree and 27 degree
A at                  B between                   C in                      D with
  77. I am preparing for the picnic ……………..  my friends tomorrow.
A at                 B to                          C in                         D with
  78. Please bring some raincoats just…………….. case.
A in                   B at                          C on                 D to
  79. It snowed in Lang Son………….. winter ……………  2002.
A in/of              B of/in                         C at/ for           D for/ at
  80. Kangaroos, which come…………..  Australia, have long tales.
A to                  B in                             C from             D for