sentence1: 3 It should be noted that the toxicity (LC50) of a sample observed in a range-finding test may be significantly different from the toxicity observed in the follow-up chronic definitive test  (1) the definitive test is longer; and (2) the test may be performed with a sample collected at a different time, and possibly differing significantly in the level of toxicity and true is true and true is true and true is true and true is true and true is true .
sentence2: The toxicity of a sample in the range-finding test might be very different from the toxicity in the follow-up test because solutions change depending on temperature.