有一假说：水果和蔬菜切开后，质量的变化可解释为是它们内部水分的蒸发散失所致。如图所示的是验证该假说的实验方案的部分情景，实验材料是均匀剖开的胡萝卜，根据图示回答下列问题：

据材料一，概括作者的核心观点。据材料一、二，指出玛雅文化艺术的重要形式。

阅读短文，然后用括号中所给词的适当形式填空。

The old newspaper seller

He is sitting at the newspaper stand near the bus stop.

And he’s  ____(smile).

The Sun is ____ (shine). It’s very hot . But he’s smiling.

A bus stops, and the people rush out . They are hurrying ____ (work). They don’t have much time to smile. They take their papers ____ (quick) , and put down some money . But he’s a patient man , and he’s still smiling.

A crowd of people , all very busy , with tired ____ (face) , and just one smile. Is there just one smile in this city? Or will you make it two? Let ____ (we) make a million smiles!