dear editor,<br /><br />one of your edited sentences (see below), I think that since less than 20 mg/L refer to plural form of concentrations, is it alright to write it as follows?<br /><br />--&gt; my edited sentence: The study by Mueller and Nowack (2008) indicated that the predicted environmental concentrations of nano-TiO<sub><span style="font-size: small;">2</span></sub>&nbsp;in water were less than 20 mg/L, which are still higher concentrations than the predicted no effect concentrations of less than 1 mg/L.<br />--&gt; OR "The study by Mueller and Nowack (2008) indicated that the predicted environmental concentrations of nano-TiO<sub><span style="font-size: small;">2</span></sub>&nbsp;in water were less than 20 mg/L (still higher concentrations than the predicted no effect concentrations of less than 1 mg/L).<br /><br />Your edited sentence: The study by Mueller and Nowack (2008) indicated that the predicted environmental concentrations of nano-TiO<sub>2</sub>&nbsp;in water were less than 20 mg/L, which is an amount still higher than the predicted no effect concentrations of less than 1 mg/L.&nbsp;&nbsp;<br /><br /><br />Also, in the following sentence, the verb form should be signular, is this right?<br /><br /><br />--&gt; my edited sentence: Our study showcases that the long-term accumulation of nano-TiO<sub><span style="font-size: small;">2 </span></sub>could have detrimental effects on marine environments.<br /><br />Your edited sentence: Our study showcase that the long-term accumulation of nano-TiO<sub>2 </sub>could have detrimental effects on marine environments.<br /><br />please let me know your opinion.<br /><br />thanks