try to do and to do正确吗？还是try to do and do？可以省略第二个to吗？

try to do and to do正确吗？还是try to do and do？可以省略第二个to吗？

try to do and do
例句
We should try to learn economic theory and apply it.
我们应努力学习经济理论并能应用。

All my teachers try their best to tell me what to do and expect me to do my best like my fellow students.
每一位老师都很尽力的告诉我在学校时该做些什麽，他们也都希望我可以和其他同学一样把自己最好的一面表现出来。

或许可以。