John opened the door . There _____ he had never seen before.

There are no customers in the hotel. It______ have the friendliest service. A．can’t

Do you still remember the day when we went to the Great Wall?— I can’t remember it well, but ________ it have been sometime last year?[ ]

azon and Wall Mart are popular websites ______ people can sell goods to eachother

The girl conquered her fear and ___ the enormous spider in sight of it last night.