11.   A high count can occur naturally, but also signal the use of the banned growth hormone EPO.

12.   A high count can occur naturally.

13.   But the high count can also occur naturally.

14.   High counts can signal the use of the banned growth hormone EPO, but also can occur naturally.

15.   Simply put, a high count of BOD and COD means the river is polluted.

16.   The high count can signal the use of the banned substance EPO, but it can also can occur naturally.

17.   The high count can signal the use of the banned EPO but also can occur naturally.

18.   The high count can signal the use of the banned growth hormone EPO, but also can occur naturally.

19.   The high count can signal the use of the banned EPO, but also can occur naturally.

20.   The high counts can signal the use of the banned growth hormone EPO, but also can occur naturally.