本题目来源于试卷: IB ESS Unit 2: Ecosystems & Ecology，类别为 IB环境系统与社会
[单选题]
State the abiotic factor that can be measured lbrt8. vn,o.j8ct*n q phogc2r))6zo using a Seccd,i:2l ibtyli 14r mw)hi disk.
A. depth
B. turbidity
C. pH
D. particle size
参考答案: B
本题详细解析:
A Secchi disk is used to measure the turbidity of freshwater, so :e1gh enu p ;/a..ey euailj/8( 4siouoption B is correct. If you can still see the Secchi disk when it is deeper, it means that t:ie/(.hu ;i e1j/pes.loa g4ea8uyun he water has less material floating in it: the turbidity is low.
The knots or marks on the rope that is used to lower the Secchi disk in the water indicate depth. However, their purpose is to indicate at which depth it is no longer possible to distinguish between the black and white areas on the disk. Option A is, therefore, incorrect.
There are various methods to measure pH, but the Secchi disk is not one of them. Option C is incorrect.
Turbidity of water is caused in part by particles in the water, but we do not generally measure these. We do measure the size of soil particles using a sieve. Option D is incorrect.
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