以下最能表明唐朝时中国人学习外国文化的开放意识和刻苦精神的是（  ）

完形填空。

    Once upon a time, a rich man and a poor man talked about what happiness was.

    The poor man said, “Happiness is 1we have now.”Seeing the poor man's old clothes and house, the rich man laughed at him and said 2“How can this be called happiness? My happiness is my huge and beautiful house with one 3rooms and a thousand servants(佣人).”

 4a windy night, a big fire happened in the rich man's house and his hundred-room house was burnt down into 5. All his servants went away and left him alone. The rich man lost 6 and he became a beggar(乞丐) overnight.

    One day, the beggar was very hungry. He came to 7 some food to eat when he passed by the poor man's house. The poor man 8him a bowl of rice, asking, “What do you think of happiness now?”

    The beggar said anxiously, “Happiness is 9 bowl of rice in your hand.”

    Happiness is all that at the moment. One 10enjoy happiness in all his lifetime only by cherishing(珍惜) what he has now.

如图是二次函数 y₁=ax²+bx+c和一次函数y₂=kx+t的图象，当y₁≥y₂时，x的取值范围是____ ．

鲫鱼适应水中生活的形态结构特点是（    ）

①背面深灰黑色，腹面白色 ②身体侧扁，呈梭形 ③体表有黏液 ④身体分头、躯干、尾三部分 ⑤具有鳍 ⑥具有鳃和鳔 ⑦身体两侧有侧线