选出合适的介词，补全句子。

（1）Yesterday I went to the supermarket __________ my mother.
（2）We need food ____________ our picnic.
（3）Please put your books _____________ your bag.
（4）There are lots ____________ people in the park.
（5）We went to the Water Park __________ nine o’clock.
（6）Please give one apple __________ every child.