--- I was walking along the street and all of a sudden, a car cut in and knocked me down.--- You can never be ______ in the street.
72. We couldn’t read the notice on the board because several people were standing _______ it.
71. People eat a lot of sugar __________ cakes, soft drinks, sweets and so on every day.
70. I know it is difficult __________ him to talk like the lecturer, but I think he should grasp every chance .
69. With the guide leading the way, the visitors were able to travel through the forest not by air but _____ foot.
68. When the boy playing by the river fell into the river, I was out of the room _______.