1 . The great pianist performed in the centre of the stage，at_______ command the keys were producing wonderful tunes（曲调）. （用适当的词填空）

2 . John invited about 40 people to his wedding, most of________are family members.

3 . China’s population is expected to increase to about 1.5 billion, after ________ it will start to decline slowly.

4 . My favorite writer is J.K Rowling, most of ________ books have been adapted for films. （用适当的词填空）

5 . There are a wide variety of activities at the festival, most of _________ are popular among young people. (用适当的词填空)

6 . We took a road map with us during our last trip, ________ we would have lost our way.

7 . There are many books on the shelf in his study, most ________ he really enjoys.

8 . There are many good websites ________ you can check out the latest news in the science world. (用适当的词填空)

9 . There are certain dates throughout the year ________ the entire country takes a vacation at the same time. (用适当的词填空)

10 . I am reading a detective story, the plots of _________attract me most.（用适当的词填空）