Originally introduced by Netscape Communications, (1) are a general mechanism which HTFP Server side applications, such as CGI (2) , can use to both store and retrieve information on the HTTP (3) side of the connection. Basically, Cookies can be used to compensate for the (4) nature of HTTP. The addition of a simple, persistent, client-side state significantly extends the capabilities of WWW-based (5) .

（4）是（）

A.fixed

B.flexible

C.stable

D.stateless

下图表示下丘脑神经细胞、垂体细胞、甲状腺细胞及它们分泌的激素之间的关系，研究表明物质乙是一种糖蛋白。请回答下列问题：

如果用物质丙饲喂正常动物，则物质甲、乙的分泌量的变化分别是（）、（）、如果用物质乙饲喂正常动物，则物质丙的分泌量（），原因是（）。