The texture of the soil depends on the
relative amounts of different-sized particles that combine to make up the soil.
These particles can be as large as stone and gravel or as small as
clay. A typical clay soil is composed of approximately 60 percent actual clay, 20 percent silt, and 20 percent sand. The particles in a sandy soil are so fine that it tends to be compact and interferes with the oxygen supply for plant roots. Water has trouble entering this impervious soil, and runoff is very common during rainfalls. A typical light sandy soil is composed of approximately 70 percent sand, 20 percent silt, and 10 percent clay. The particles in a sandy soil are comparatively large, permitting water to enter the soil and to pass through it so quickly that it often carries nutrients with it and dries out very rapidly. The texture of sandy soils is genera A. To tell gardeners how to modify their soil. B. To classify soil types on the basis of their composition. C. To illustrate the effects of soil type on plant growth. D. To show how water is absorbed by different soil. [单项选择]“太阳少阳并病,而反下之”,则成()
A. 发黄 B. 惊悸 C. 痞证 D. 谵语 E. 结胸 [填空题]列车运行是以车站、线路所所划分的区间及自动闭塞区间的通过信号机所划分的( )作间隔。 J308
[多项选择]膳食调查通常采用的方法有( )
A. 称量法 B. 查帐法 C. 24小时回顾法 D. 平衡代谢法 [单项选择]单位通风量是指每小时每()粮食所需的风量。
A. 10000公斤 B. 500公斤 C. 5000公斤 D. 1000公斤 [简答题]P0口用作通用I/O口输出数据时应注意什么?
[单选题]作业票签发人是负责该项作业的()。
A.技术负责人 B.安全负责人 C.安全监护人 D.施工负责人 E.略 F.略 [多选题] 下列违反《人民警察使用警械和武器条例》规定的情形是( )。
A. 几十个下岗工人在市中心区非法举行游行、示威,民警要求解散,经警告无效,鸣枪示警 B. 民警张某在街上巡逻时受到几名青年的言语谩骂,警告不听,于是用警棍将他们制服 C. 一伙人聚众扰乱车站,影响恶劣,经劝阻不听,民警用高压水枪将他们驱逐 D. 民警在讯问犯罪嫌疑人吴某时,吴某欲自杀,民警用警绳将其捆绑 [单项选择]关于工程进度款的支付,《施工合同文本》中有如下规定,工程款在双方确认后( )内,甲方应向乙方支付工程款。
A. 7日 B. 14日 C. l5日 D. 28日 [判断题]出世以后,人的生长发育有三次较快的突增期。
[单项选择]以下不属于组织实体基本构成要素的是()
A. 领导者 B. 职责 C. 职权 D. 负责关系 [单选题] 给水泵( )不严密时,严禁启动给水泵。
A.进口门; B.出口门; C.再循环门; D.出口逆止门。 [多选题]《国家电网有限公司输变电工程施工安全风险识别、评估及预控措施管理办法》按照()的原则,对输变电工程施工安全风险进行管理。
A.初步识别 B.复测评估 C.分级控制 [填空题](208690)基础制动装置组装完毕应进行充风试验制动缸的( )功能。(2.0分)
[单选题]《铁路旅客运输规程》第二十条规定,华侨和港澳台学生,每年可购()次学生票。
A.4 B.6 C.8 D.10 [单项选择]咯血最常见的原因是
A. 肺淤血 B. 肺炎 C. 肺结核 D. 支气管肺癌 E. 肺梗死 我来回答: 提交
|