宋代词人辛弃疾在词中写到“稻花香里说丰年，听取蛙声一片”，夏季青蛙高昂鸣叫的意义是（    ）

    This is a picture of Mr. Li's family. The man in the middle is Mr. Li. The woman is Mr. Li's wife. They have two sons. The child behind Mr.Li is Li Lei. He's thirteen. The other in front of Mrs. Li is Li Ming. He is eleven. Li Lei and Li Ming are in the same school, but not in the same grade. Li Lei is in Grade Two. Li Ming is in Grade One. They are good students.

已知：I．RONa+R′X→ROR′+NaX；

II．RCHO+R′CH₂CHO $\stackrel{稀N\text{a}OH,\Delta }{\to }$ +H2O（R、R′表示烃基或氢）

I can see six ________in the room.