As soon as the children _____ themselves in their seats in the classroom, the bell rang.
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.
How I wish I you there too yesterday!