下列命题：（1）一个圆的内接三角形有且只有一个；（2）一个三角形有唯一的一个外接圆；（3）过一直线上两点和它外一点可以确定一个圆；（4）已知三点A，B，C，过这三点可以作并且只可以作一个圆．其中假命题的个数是（   ）

如图是动物某分泌细胞．向细胞内注射用放射性同位素3H标记的氨基酸，一段时间后，在细胞外检测到含有放射性的分泌蛋白质．请回答下列问题（内填序号）：

根据对话内容，从方框中选择恰当的选项补全对话，其中有两项多余

A: Linda, are you free this evening?

B: Not really! Why?

A: Some of our classmates are coming to my home for dinner. ____

B: I' m afraid not. ____

A: At about eight o' clock.

B: ____

A: What about half past six?

B: Oh, I promised my brother I would help him with math at that time.

A: ____

B: But I will come over to your house next time.____

A: You're welcome.

A. Sure, I'd love to. B. Can you come, too? C. OK, you are really busy. D. But when will the dinner start? E. I' m going to your house by bike. F. Thank you very much for asking me. G. Oh, sorry, I have a violin lesson at that time.

阅读判断。
    Jenny, Danny, Kim and Steven are good friends. Jenny and Kim are reading books in the library. Where are Danny and Steven? Look! They are playing a game on the playground. Who is in the classroom? It's Mr. Wood.

女性的卵巢和输卵管通常被称作子宫的附件．下列说法正确的是（　　）