___ in the reading room alone quite by accident, the boy felt nervous.

We often provide our children with toys, footballs or basketballs, ______ that all children like these things. [ ]

This is a______ but extremely difficult technology in the future.

The government is ________ to everyone to save energy in order to carry out the construction of “twooriented society” in Wuhan and other circle cities.[ ]

id you find your visit to the museum, Jane—________