Related Questions

In order to protect the aquatic creatures, the dissolved oxygen content in fresh water stream should never be less than __________ PPm.
A 0.5
B 1
C 5
D 20
Dissolved oxygen content in river water is around __________ ppm.
A 5
B 100
C 250
D 500
The minimum dissolved oxygen which should always be present in water in order to save the aquatic life is
A 1 ppm
B 4 ppm
C 10 ppm
D 40 ppm
A. there was the hope that in another existence a greater happiness would reward one B. previous existence and the effort to do better would be less difficult too, when C. it would be less difficult to bear the evils of one's own life, if D. One could think that they were but the necessary outcome of one's errors in a
A CDBA
B BADC
C BDCA
D CABD
শাকিলের প্রস্তুতকৃত দ্রবণের i. ppm একক হবে 40000 ppm ii. মধ্যে আরো 10 mL পানিযোগে সেমিমোেলারে পরিণত হবে iii. মধ্যে 6.02 × 1022 টি NaOH অণু রয়েছে নিচের কোনটি সঠিক?
A i ও ii
B i ও iii
C ii ও iii
D i, ii ও iii
The relative stability of a sewage sample, whose dissolved oxygen is same as the total oxygen required to satisfy BOD, is
A 1
B 100
C Infinite
D Zero
Bromine content in sea water may be around __________ ppm.
A 70
B 640
C 1875
D 2500
Presence of __________ in water stream are deleterious to aquatic life.
A Soluble and toxic organics
B Suspended solids
C Heavy metals and cynides
D All of the above
What environmental issue involves the excessive use of fertilizers and run-off chemimls into bodies of water. causing oxygen depletion and harm to aquatic ecosystems?
A Acid rani
B Eutrophication
C Desertification
D Deforestation
L is older than M and taller than N. O is younger than P, older than N and shorter than Q. R is older than S, younger than N, shorter than S and taller than Q. S is older than L, M, O, P, Q, R and S is necessarily false?
A O is the shortest of the group.
B N is the second tallest of the group.
C L is the tallest of the group.
D Q is the third oldest of the group.

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