科学家研究发现紫外线可以抑制植物生长,原因是紫外线增加了植物体内吲哚乙酸氧化酶的

题型:实验题

问题:

科学家研究发现紫外线可以抑制植物生长,原因是紫外线增加了植物体内吲哚乙酸氧化酶的活性,从而促进了生长素氧化为3-亚甲基氧代吲哚,而后者没有促进细胞伸长的作用。现在提供生长状况相同的健康的小麦幼苗若干作为实验材料,请完成下列实验方案,以验证紫外线抑制植物生长与生长素的氧化有关。

(1)步骤1:将小麦幼苗平均分为甲组和乙组。

(2)步骤2:给予甲组___________光照,给予乙组_________光照。

(3)步骤3:观察两组幼苗的__________并测量_____________的含量。

(4)预测实验结果及结论:_____________________________________。

考点:生长素的生理作用科学研究方法
题型:实验题

根据句子意思和所给中文或首字母提示,写出单词的正确形式。(共10小题;每小题1分,满分10分)

小题1:You must tell us ______ (确切地) how much money you will need besides that sum.

小题2:Chairman Mao compared ______ (青少年) to the rising sun in the morning.

小题3:Although she is Chinese, she can speak English, French and German ______ (流利地).

小题4:The boy is afraid of the dark, so he likes sleeping with ______ (窗帘) pulled and the light turned on.

小题5:Go ______ (径直地) ahead until you come to a bank. You won’t miss it.

小题6:I said Hello to her, but she i______ me completely.

小题7:He still didn’t r______ from the death of his mother.

小题8:Police are trying to discover the i______ of a baby found outside their offices.

小题9:She is no longer u______, because her problem has been solved.

小题10:Jane and Mary are good friends; the former is a teacher, and the l______ is a nurse.

题型:实验题

四个数一定能组成比例。[ ]

题型:实验题

在解答问题的过程中,对解答问题有启示作用的相类似的事物叫做( )。

A.原型

B.原型启发

C.问题情境

D.问题对象

题型:实验题

如图3.3.2.2所示,基础底面尺寸为4.8m×3.2m,埋深1.5m,相应于荷载效应准永久组合时,传至基础顶面的中心荷载F=1800kN,地基的土层分层及各层土的压缩模量(相应于自重应力至自重应力与附加应力之和段),用应力面积法计算基础中点的最终沉降量为()mm。

A.128.3

B.132.9

C.141.7

D.147.3

题型:实验题

散热器组对时应二人一组,严格按照操作程序进行配合组装。

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