1. 不要在河边玩耍。
     _______ _______ near the river.
2. 我认为我在家里受的约束太多.
     I think I have _______ _______ rules at home.
3. 周末，你不必穿校服。
     On _______, you _______ have to wear a school uniform.
4. 此处禁止吸烟。
     _______ _______ here.
5. 上体育课时我们必须穿运动鞋。
     We _______ _______ wear sneakers for PE classes.