求达人帮忙看看，这道题该怎么做，要有过程哦，谢谢 求达人帮忙看看，这道题该怎么做，要有过程哦，谢谢
在前面学生对种子的构造有了一定的认识，知道双子叶植物的种子是由种皮和胚构成的；单子叶植物的种子是由种皮、胚乳、胚构成的；胚是由胚根、胚芽、子叶构成的。还知道胚是有生命的，能发育成一棵新的植物。但是对于得到萌发条件的种子是怎样萌发成一棵幼苗的这一生命现象,学生感到很好奇。他们想知道弱小的的幼苗是怎样破土而出的?胚根是怎样发育成植物根的?胚芽是怎样发育成植物茎和叶的?子叶，胚乳在种子萌发时起什么作用?种皮在种子萌发后怎么样了?胚根向什么方向生长?学生的众多疑问，使我认为这个实验应设计成一个近似于自然界中种子萌发时的情景。
为了能较准确地反映种子萌发时的自然水平，又便于学生的观察，我对这一试验进行了改进，具体做法如下：
在无色透明的玻璃杯或塑料杯(无色透明的饮料瓶去掉上半部分也可以)中放上滤纸或其他吸水纸，使纸从杯底到杯口紧贴杯壁。在杯中装入锯末或土壤，使土壤或锯末略低于杯口滤纸上沿。把浸泡过的种子“种”在杯壁和滤纸之间约2厘米深的位置。在杯内浇上水，转动杯子，使滤纸完全湿透，注意杯内的水不能淹没种子。把种子放在温暖的地方，每天注意观察并将结果记录下来，缺水时及时补充，这样就可以较准确地反映出种子萌发时的自然水平了，也便于观察者通过透明的杯壁观察种子萌发的过程。
求这道题的解 最好有过程 谢谢！~
这是永续年金。很简单。把年收益率换成半年收益率。
There has been a long time since I came back from Hainanwow,hainan is such a wonderful place that I will never forget it .It's really a good place where gave me a rather good impression. I feel so wonderful during the journey, as I have ex
There has been a long time since I came back from Hainan—wow,hainan is such a wonderful place that I will never forget it .It's really a good place where gave me a rather good impression. I feel so wonderful during the journey, as I have experienced a lot of things for the first time.
In January 7th ---the first day of my journey, the fluttering snowflakes diffused over Changzhou. I first took the train to shanghai then took the plane to Hainan in Pudong airport. Although it’s my second time to take plane, I felt even more excited than the first time. When flying, I found that I was flying over the cloud of different types and colors. The sky is also brighter and clearer than that I had ever seen. Soon we arrived in Meilan airport in Haikou, the climate is totally different from that in Changzhou, It was warm there and we could see coconut trees everywhere.
After 3 days competition, I went to BoAo where is famous for its forum. It was my first time to experience the sea and the beach in the sunshine. When sitting on the cruise, I could clearly see the ocean waves pushing the windows of the cruise. It seemed that I was surrounded by the waves and the crystal water. I felt as if a fish which had been living in the sea happily. Then we land on the beach. The sand on the beach was so soft that it was cosy to lie on the beach. I tried searching for the shells on the beach but failed. The beach was totally different from what I heard before as there was nothing except footsteps on the beach. In the afternoon, I played football on beach and scored a goal with my new friends from all around China. It was really interesting and challenging.
The next day, I went to Haikou. I first visited the tomb of Hairui, an officer in Qing dynasty who was famous for rectitude. I think he should be the role model of every person. In the afternoon, I went to the geological park of volcano. A lot of stones of different shapes came into views. When arriving the top of the park, it seemed that the while city was under my view. Also I had seen plenty of interesting and rare types of the plants. I also got into a small hole in the park, it is said that the hold was exactly the original hole where maqma came from. But the volcano had stopped from eru
求达人帮忙看看,这道题该怎么做,要有过程哦,谢谢
答：5/8—3/10 =25/40—12/40 =13/40 7/10—1/15 =21/30—2/30 =19/30 7/8+5/16 =14/16+5/16 =19/16 17/18—5/6 =17/18—15/18 =2/18
求达人帮忙看看,这道题该怎么做,要有过程哦,谢谢
答：⑵ y=-2x2+120x-1600 =-2 (x-30) 2+200,∴当x=30时,y有最大值200.∴当销售价定为30元/千克时,每天可获最大销售利润200元.⑶ 当y=150时,可得方程 -2 (x-30 )2 +200=150.解这个方程,得 x1=25,x2=35.根据题意,x2=35不合题意,应舍去.∴当销售价定为25元/千克时,该农户...
求达人帮忙看看,这道题该怎么做,要有过程哦,谢谢
答：解：设有x张球台是单打，则有 12-x 张球台是双打。2x + 4 * (12-x)= 34 == 2x + 48 - 4x = 34 == -2x = -14 == x = 7 (张)12 - x = 12 - 7 = 5 (张)答：有7张球台是单打，有5张球台是双打。
求达人帮忙看看,这道题该怎么做,要有过程哦,谢谢
答：C=32×2×3.14+100×2 =64×3.14+200 =200.96+200 =400.96m S=32×32×3.14+（32×2）×100 =1024×3.14+64×100 =3015.36+6400 =9615.36m²
求达人帮忙看看,这道题该怎么做,要有过程哦,谢谢
答：回答：设:第二车间人数为x,则第一车间人数为4/5x-20; 人数抽调之后,第一车间剩下x-10人,第二车间剩下4/5x-20+10人, 这时候有:4/5x-20+10=(x-10)*3/4,解得x=50人。 答:第一车间有20人,第二车间有50人。
求达人帮忙看看,这道题该怎么做,要有过程哦,谢谢
答：回答：2x+80=480 解:2x+80-80=480-80 2x=400 2x÷2=400÷2 x=200
求达人帮忙看看,这道题该怎么做,要有过程哦,谢谢
答：一共50元买衣服，花去20元剩余30元50减20等于30买拖鞋花去15元剩余15元30减15等于十五百八十九元剩余六元15减9等于6买食品花去六元剩余0.6减6等于0
求达人帮忙看看,这道题该怎么做,要有过程哦,谢谢
答：解设直径为X 2X+3.14X=10.28×2 5.14X=21.56 X=4 直径为4（厘米）面积：3.14×（4÷2）×（4÷2）=3.14×2×2 =12.56（平方厘米）
求达人帮忙看看,这道题该怎么做,要有过程哦,谢谢
答：回答：先算出圆形牛栏的面积 3.14×15×15=706.5(平方米) 知道每头牛的占地面积,那么牛栏可以关的牛数就是353头 (706.5÷2=353.25 )
求达人帮忙看看,这道题该怎么做,要有过程哦,谢谢
答：（2）求加油前油箱剩余油量y与行驶时间t的函数关系式;（3）已知加油前后汽车都以70千米/小时的速度匀速行驶，如果加油站距目的地210千米，要到达目的地，问油箱中的油是否够用？请说明理由．解：（1）由图可知汽车行驶3小时后加油，加油31升．（2）根据题意，设所求函数关系式为y＝kt＋b．因此函数...
