求解答这两道英语单项选择题,感激不尽.

求解答这两道英语单项选择题,感激不尽.
Several girls ____ towards the playground at about nine o'clock.
[A] were seen run
[B] saw running
[C] were seen running
[D] This new invention is ____ to be of great importance to our lives. have been seen running
This new invention is ____ to be of great importance to our lives.[A]
bound[B]
substantial[C]
operational[D]
indifferent