寄托天下
查看: 1215|回复: 1
打印 上一主题 下一主题

[求助] TPO5最后一题求教 [复制链接]

Rank: 2

声望
4
寄托币
260
注册时间
2007-3-14
精华
0
帖子
24
跳转到指定楼层
楼主
发表于 2010-6-16 02:55:44 |只看该作者 |倒序浏览
TPO5最后一个问题, 我怎么看都觉得2是错的, Though beneficial in lower levels, 这句话和文中提到的 "lower levels会影响植物"相矛盾啊. 希望高手解答一下. 谢谢!


Plantsneed to absorb certain minerals from the soil in adequate quantities for normalgrowth and development.







Answer Choices
1. Someplants are able to accumulate extremely high levels of certain minerals andthus
can be used to clean up soilscontaminated with toxic levels of these minerals.

2. Thoughbeneficial in lower levels, high levels of salts, other minerals, and heavymetals can be harmful to plants.
3. Whenplants do not absorb sufficient amounts of essential minerals, characteristicabnormalities result.
4. Becausehigh concentrations of sodium chloride and other salts limit growth in mostplants, much research has been done in an effort to develop salt-tolerantagricultural crops.
5. Someplants can tolerate comparatively low levels of certain minerals, but suchplants are of little use for recycling nutrients back into depleted soils.
6. Mineraldeficiencies in many plants can be cured by misting their roots with a nutrientsolution or by transferring the plants to a soilless nutrient solution.
回应
0

使用道具 举报

Rank: 2

声望
4
寄托币
260
注册时间
2007-3-14
精华
0
帖子
24
沙发
发表于 2010-6-17 01:06:29 |只看该作者

使用道具 举报

RE: TPO5最后一题求教 [修改]
您需要登录后才可以回帖 登录 | 立即注册

问答
Offer
投票
面经
最新
精华
转发
转发该帖子
TPO5最后一题求教
https://bbs.gter.net/thread-1111080-1-1.html
复制链接
发送
报offer 祈福 爆照
回顶部