场景分类上生物第十五篇0 @5 L2 a8 \* X
health agent,biological agent是什么意思？

我觉得选D

熊猫，你写下原文位置呗，要不没人有耐心找出那篇

ok,
% |# ~% K, V; z( d# J9 g9 s场景分类上生物第十二篇第六题
2 O, r1 o/ r1 c" ]3 Twhat did the discovery of the  Protoavis lead the scientists to believe?( V# `2 o! W% s* |; a8 j+ o
A:the Archaeopteryx was probably the first reptile with wings+ x9 P% I# n/ d( @) |% q
B:birds were not the members of the reptile family
' P( C* Z; f5 i: S0 I# ?  NC:early members of the bird family didn't have feathers
; @9 b3 ]3 r  l) C+ }7 \- ^D:birdlike creatures exist much earlier than previously thought
3 {  u9 s1 c, g9 U: v9 {( F$ g/ C, K( k- I. d3 ^/ I8 _! X
[ 本帖最后由 功夫熊猫2 于 2008-8-12 14:41 编辑 ]

场景分类下生物，实验介绍
8 C7 [$ U" J) R8 W4 Y; Z1 jworkbook是什么意思？
+ s; D3 W- r, S" ]+ owhat you're supposed to do is choose the experiments and activities you want to do ,within a certain framework of course是什么意思？

有人吗？很急

        In 1906 a British geologist discovered that P waves slowed down at a certain depth but kept traveling deeper. On the other hand, S waves either disappeared or were reflected back, so he concluded that depth marked the boundary between a solid mantle and a liquid core核心, 精髓, 要点. Three years later another boundary was discovered  that between the mantle and the Earth's crust.地壳

PS 场景下 地球科学第一篇

不懂～～～～～～～

我靠 3天过去了 没人理我啊

引用:

原帖由 功夫熊猫2 于 2008-8-14 17:04 发表 3 d/ a5 N2 k! c2 _" g
场景分类下生物，实验介绍
, A, K5 _+ \2 x6 W5 ]' Gworkbook是什么意思？& Q7 r9 J( i; B6 ]/ G% o  Y
what you're supposed to do is choose the experiments and activities you want to do ,within a certain framework of course是什么意思？  

( a% X8 s* \3 a# q) ], C6 @& x' A  _" J- W/ c  l9 f! L5 x

4 R7 A3 `1 t6 Dworkbook实验手册- V# k0 o' E& F+ E' y
你所要做的就是选择你想做的实验或activities，这些实验或activities是在一定的框架内的

In 1906 a British geologist discovered that P waves slowed down at a certain depth but kept traveling deeper. On the other hand, S waves either disappeared or were reflected back, so he concluded that depth marked the boundary between a solid mantle and a liquid core核心, 精髓, 要点. Three years later another boundary was discovered  that between the mantle and the Earth's crust
3 ?: `1 z3 i; @$ ]. b3 S5 W( e3 x
) @, v1 D6 L8 j% W1 e在1906年有位英国地质学家发现P波到一定深度后虽然可以继续下行速度却下降了，而s波要么消失要么被返回了，因而他总结出在那个深度的固体地幔和液体核心之间有个边界。三年之后在地幔和地壳之间发现了另一个边界。% n, ^) U8 d. S, D# e# f

2 |; N9 e/ @0 I, S3 B4 w! z* }$ sPS：达达，你是具体那句不理解吧，也没说清楚，就拿整段的整段的折磨我们