The man we followed suddenly stopped and looked as if ________ whether he was going in the right direction.
A．seeing B．having seen
C．to see D．to have seen
Only ________ according to the directions can the medicine be quite effective.
A．taking B．taken
C．being taken D．having been taken
—We didn't find the Blacks ________ the lecture.
—No one had told him about ________ a lecture the following day.
A．to attend；there to be B．attending；there being
C．attended；there be D．attend；there was
A few days after the interview，I recevied a letter ________ me admission to the university.
A．offering B．offered
C．having offered D．to be offered
—Why do you look sad?
—There are so many problems ________.
A．remaining to settle B．remained settling
C．remaining to be settled D．remained to be settled
________ as the “first lady of speech”，Dr, Lillian Glass is recognized as one of the world's leading experts on communication skills.
A．Knowing B．Having known
C．Known D．To be known
