Passengers are permitted only one piece of hand luggage onto the plane.
he worked hard, he still failed to finish the task in time.
When he was young, he used to hard at his lessons.
They are just human creatures in a human environment, trying to themselves to a social situation
_ much difficulty we may meet, we will finish the work in time.
The moment the ambulance(救护车)came to the hospital, the sick man to the operation room.