大学英语四级考试听力模拟试题(十一)

　　w: maybe instead of keeping them in the corner, you should put them directly in front of the window.

　　q: what does the woman imply?

　　17.w: bob, shall i cut your hair for you?

　　m: you must be kidding. last time you almost made me bald.

　　q: what does the man imply?

　　18.m: this scarf is nice, but debbie really wanted a sweater for her birthday.

　　w: i know. but i didn’t know her size. so i got this as an alternative.

　　q: what can be inferred from this conversation?

　　now you will have two long conversations.

　　w: well, that’s an assumption many people make. but the fact is that bones are made of dynamic living tissue that requires continuous maintenance and repair.

　　m: right. that’s one of the things i found so fascinating about the article---the way the bones repair themselves.

　　w: ok. so can you tell us how the bones repair themselves?

　　m: sure. see, there are two groups of different types of specialized cells in the bone that work together to do it. the first group goes to an area of the bone that needs repair. this group of cells produces the chemical that actually breaks down the bone tissue, and leaves a hole in it. after that the second group of specialized cellses and produces the new tissue that fills in the hole that was made by the first group.

　　w: very good. this is a veryplex process. in fact, scientists who study human bones don’tpletely understand it yet. they are still trying to find out how it all actually works. specifically, because sometimes after the first group of cells leaves a hole in the bone tissue, for some reason, the second group doesn’tpletely fill in the hole. and this can cause real problems. it can actually lead to a disease in which the bone bes weak and is easily broken.

　　m: ok, i get it. so if the scientists can figure out what makes the specialized cells work, maybe they can find a way to make sure the second group of cellspletely fills the hole in the bone tissue every time. that’ll prevent the disease from ever occurring.