右图为人体生长激素分泌的调节示意图。

（1）细胞a分泌的激素对细胞c的分泌具有促进作用，而细胞b分泌的激素对细胞c的分泌具有抑制作用，则这两种激素对细胞c分泌生长激素的调节呈____ 关系。若生长激素分泌增多，将____ （填“促进”或“抑制”）细胞b的分泌。

（2）下丘脑是神经系统和内分泌系统联系的枢纽，如发生急性低血糖时，对血糖浓度敏感的神经元可通过细胞a促进细胞c分泌。在这个调节过程中，下丘脑神经内分泌细胞的作用是将____ 转变为____  。

（3）激素的作用范围较广泛，如生长激素可与全身脂肪细胞和软骨细胞等靶细胞的受体结合并发挥作用，这是因为____ 。

（4）运动能提高机体免疫功能，原因之一是生长激素可作用于胸腺，促进____ 分化。

下列有关保卫细胞的说法中，正确的是（    ）

——Would you like to come to my house for dinner tonight?
——I'd love to , _____ I have lots of work to do .

     Mr. Green lives in a big city with his wife and two children. One morning Mr. Green takes his new car and washes it when a friend comes. The friend stops and looks at the new car for a minute. Then he asks, "That's a new car. Is it yours? "
"Sometimes." Mr. Green answers.
   The friend is surprised (惊奇). "Sometimes? " he says. "What do you mean?" Mr. Green answers slowly, "Well, when there is a party in town, my daughter Jean drives it. When there is a football, it's my son Jim's turn. When I washes it and it looks very nice and clean, my wife Linda uses it. And when it needs cleaning. It's mine. Choose the correct answer.