7∶4和 $\frac{1}{7}$ ∶ $\frac{1}{4}$ 可以组成比例。

明朝后期的李贽“离经叛道”，自称异端，向正统思想挑战；文艺复兴时期的薄伽丘在《十日谈》中抨击封建道德和教会的禁欲思想，二者在本质上都反映了  

如果 那么 ×31＝____。

    Layla and her family were driving to the town park. It was a hot day. She wanted to swim in the lake. As they got out of the car, Layla saw ____ friends.

    "Let's go into the water!" she called. All the kids jumped in ____.

    Layla always has fun at the park. In spring, Layla's dad often takes her fishing, in the ____ They usually go early in the morning. The lake water is still (平静的). It is different ____ the river, which has water that runs by.

    In ____ families have picnics near the lake. The kids play and swim in the lake.

    In the morning of autumn, the lake has fog (雾) over it. Layla's dad once ____her something about fog: Hot summer days warm the water, and then cool autumn air ____ over the lake's warm water. The water vapor (水蒸气) in the air gets cool. It ____ small drops of water (水珠). We can see those drops of water hang in the air as fog.

    Layla loves winter at the park, too. The ____ temperatures turn the water into ice. Many people go skating on the ice.

    The lake looks different at different times of the year ____ it is always a good place to have fun!