在幼林时期进行的抚育采伐是（）。A、透光伐B、疏伐C、生长伐D、卫生伐

分析回答有关光合作用的问题：试管苗的光合作用能力较弱，需要逐步适应外界环境才能往大田移栽。研究人员进行了“改变植物组织培养条件缩短试管苗适应过程”的实验，实验在适宜温度下进行，图甲和图乙表示其中的两个实验结果。请回答：

(1)图甲的实验是在大气CO₂浓度下进行的，据图分析，试管苗在不加蔗糖的培养基中____和____更高。

(2)图乙是试管苗在密闭、无糖培养基条件下测得的24h内CO₂浓度变化曲线。图中b-c段CO₂浓度升高缓慢是因为___________________，c-d段CO₂浓度急剧下降是因为试管苗_________________。若d点时打开培养瓶塞，试管苗的光合速率将_______。

(3)根据上述实验结果推知，采用无糖培养基、____________和_____________可缩短试管苗的适应过程。

病毒性心肌炎患儿见心悸、胸闷憋气，心前区痛，面色晦暗，时时呕恶，舌质淡紫，脉结代。辨证属（）

A.心脉瘀滞

B.湿热侵心

C.正虚邪恋

D.心阳虚弱

E.痰瘀互阻

Questions l-5 are based on Passage One:Passage OneLong bus rides are like television shows. They have a beginning,a middle, and an end-with commercials thrown in every three or four minutes. The commercials are unavoidable. They happen whether you want them or not. Every couple of minutes a billboard glides by outside the bus window. “Buy Super Clean Toothpaste”“Drink Good’n Wet Root Beer.”“Fill up with Pacific Gas.”Only if you sleep, which is equal to turning the television set off,are you spared the unending cry of "You Need It! Buy It Now!"The beginning of the ride is comfortable and somewhat exciting, even if you’ve traveled that way before. Usually some things have changed-new houses, new buildings, sometimes even a new road. The bus driver has a style of driving and it’s fun to try to figure it out the first hour or so. If the driver is particularly reckless or daring, the ride can be as thrilling as a suspense story. Will the driver pass the truck in time Will the driver move into the right or the left-hand lane After a while, of course, the excitement dies down. Sleeping for a while helps pass the middle hours of the ride. Food always makes bus rides more interesting.But you’ve got to be careful of what kind of food you eat. Too much salty food can make youvery thirsty between stops.The end of the ride is somewhat like the beginning. You know it will soon be over and there’s a kind of expectation and excitement in that. The seat, of course, has become harder as the hours have passed. By now you’ve sat with your legs crossed, with your hands crossed behind your head. The end comes just at the right time. There are just no more ways to sit.

The writer thinks that the end of the ride is somewhat like the beginning because both

A． exciting

B．comfortable

C． tiring

D．boring

简述红树林生态系统的特征。

代办股份转让系统是一个以证券公司及相关当事人的契约为基础，依托证券公司的技术系统，以证券公司代理买卖挂牌公司股份为核心业务的股份转让平台。( )