71. In the 1970s.

72. They are freestyle, ramp and street-style.

73. This was a combination of freestyle and ramp.

74. Because this allowed them to skateboard safety.

75. Yes, it is and there are lots of competitions.

IX.

76. I took part in swimming competition at school last week and won third prize.

77. I can't play soccer with my classmates this afternoon because I have to visit my grandmother in the hospital.

78. I should finish my homework before playing sports.

79. I do judo twice a week and go to a dance class too.

80. Soccer or football is the most popular sport in Vietnam.

71: It in 1970

72: At first, skateboarders moved slowly on flat, smooth areas. Then they began to ride quickly. Soon tey were skatebording skillfully up ramps and doing tricks in the air.

73: A combination of freestyle and ramp