66. The Summer Palace is one of the _____ parks in Beijing. I suggest you going there to have a visit.
While crossing the street, an old man was knocked down by a car and badly .
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.