The students were ____ over the ____ problem, listening to the teacher with a ____
expression on their faces.
| A．puzzled; puzzling; puzzling | B．puzzled; puzzling; puzzled |
| C．puzzling; puzzling; puzzled | D．puzzling; puzzled; puzzling |
_______ difficulties we may com across, we'll help one another to overcome them.
| A．Wherever | B．Whatever | C．However | D．Whenever |
So little known _____ that soldiers had to ask for a guide.
| A．by this earthquake - stricken area |
| B．this earthquake - stricken area |
| C．was this earthquake - strcken area |
| D．this earthquake - stricken area had been |
This monument was built in honor of the scientist who was believed ______ the first telephone.
| A．to invent | B．to have been invented | C．to have invented | D．having been invented |
I have kept that picture ______ I can see it every day,as it always reminds me of my university days in London.
| A．which | B．where | C．whether | D．when |
I wonder what notes he made in the back of his diary ______ things to mend or replace.
| A．by | B．in | C．with | D．of |