阅读短文，完成下列任务

　　The picture that sits on my desk in my bedroom is my favourite. (A)When I have trouble studying, or I’m worried about an exam, I always take a look at it. It is a picture of my best friends taken three years ago when we were in middle school. It reminds(使……想起) me of the good time we’ve shared and the support(支持) their friendship still gives me today. Our lives have gone in different directions, (B) _______ our friendship we created has kept us close. Every week I get a message on my answering machine from one of them, or a letter in the mail with the latest news or vacation photos. I often get an email with a joke for the day or words of comfort about some problems in my life. My friends often show up for surprise birthday parties, and one of them (C) _______ travelled two hours from the other end of town just to watch my first English speech contest. Our friendship has carried me through a lot of difficult experiences, and has enriched the good ones.

在细胞有丝分裂过程中，DNA分子数目相同而染色体数目不同的时期是（ ）

试比较$\sqrt{5}-1$与$\sqrt{2}$的大小，并写出推理过程．

生活实践 
一天，李奶奶到市场买东西。在一个食品摊位前，商户热情地请李奶奶尝一尝。李奶奶一尝，觉得不好吃，不想买。可是商户以李奶奶尝过为由，强迫李奶奶买一斤。吃过食品后，李奶奶觉得肚子疼，拿出包装袋一看，发现食品早过期了。