在下面算式合适的地方添上+、-、×，使算式成立。
1 2 3 4 5 6 7 8=1
1+2×3-4+5-6+7-8=1
根据句意及图片提示完成单词。
1. There are many students in the ______ ( ).
2 . I can ride a bike, but I can't ride a ______ ( ).
3. My father is a factory ______ ( ).
4. -Is your father a ______ ( )?
-Yes, he is.
5. Welcome to the ______ ( ), I'm a manager here.
压电传感器里常见的压电元件有石英晶片、压电陶瓷和分子材料三种。
). 
). 
). 
)? 
), I'm a manager here.