霉素能促进豌豆茎节间的伸长,生长素也可以促进茎的伸长。某同学设计了如下的实验来验证:

题型:填空题 案例分析题

问题:

霉素能促进豌豆茎节间的伸长,生长素也可以促进茎的伸长。某同学设计了如下的实验来验证:赤霉素与生长素具有协同作用。

实验步骤:

①取生长状况相同的豌豆幼苗,从豌豆幼苗的同一部位切取等长的茎段若干段,平均分成两组。

②将两组豌豆茎切段分别放入两个标号为A、B的培养皿中(培养液的成分见下图),在相同且适宜的条件下培养。

③每隔12小时,测量茎切段长度一次,48小时后计算茎切段伸长的平均值。实验结果见下图曲线。

请参照上述实验完善实验,写出你补充的实验设计,并预测整个实验的结果,同时根据结果得出结论。

应补充的实验

第三步:()

考点:高中生物植物激素调节植物激素调节题库
题型:填空题 案例分析题

阅读理解。

     My mother was telling me about how she and her family got their first television when she was a

teenager. Of course it was black and white. She said she only watch it at night. She doesn't remember

over watching it in the morning or afternoon. When I was young we had only about 3 or 4 different

channels. My bothers, my sisters and I would sometimes fight about which channel to watch. But we

usually enjoyed the same shows.

     Nowadays we can get hundreds of channels on TV. I can't believe it! There are channels with old

movies, cooking, fishing and so on. It's amazing! There is a channel for everything. I wonder how much

my bothers, my sisters and I would fight if we had hundreds of channels when I was a child. Of course

we had only one television set. These days I notice families with 2 or 3 or more television sets in their

homes. I guess it stops people from arguing over which channel to choose from.

1. In those days, what kind of television sets did people only have?

A. Black and white. 

B. Colors Ones.

C. All kinds of televison set.

2. My mother watched TV _____ when she was young.

A. in the morning

B. in the afternoon

C. at night

3. Nowadays, how many channels can we get on TV?

A. 3 or 4 different channels.

B. Only once channel.

C. Hundreds of channels.

题型:填空题 案例分析题

如果▲×△=□,下面哪个式子正确?______

A.▲×△÷□=lB.□=△÷▲C.△=口×▲D.▲=口×△E.△=▲÷□

题型:填空题 案例分析题
下列式子是利用平方差公式的是(  )
A.a2+b2=(a+b)B.-x2-2xy-y2=-(x+y)2
C.-a2-b2=(a+b)(a-b)D.a2-b2=(a+b)(a-b)
题型:填空题 案例分析题

商周王权是怎样发展的?

题型:填空题 案例分析题

北部湾经济区要重点发展(),形成以石化、能源、钢铁、海洋生物工程等为重点的现代临海产业集群。

A、临港产业

B、海洋产业

C、第一产业

D、旅游产业

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