1.exercise.
2.unable.
3.taxi.
4.problem.
5.human.
6.obey.
7.rocket.
8.speed.
9.wheels.
10.electricity,sky.
根据首字母填空.（ ）就是内容了
1.exercise.
2.unable.
3.taxi.
4.problem.
5.human.
6.obey.
7.rocket.
8.speed.
9.wheels.
10.electricity,sky.