Hi Xue, I hope you find the following suggestions/amendments helpful. “… The efficacy is not bad, with a 34% (over 1/3 ) reduction in cough frequency, which demonstrates its effectiveness … and the onset time of less than 2 weeks is acceptable for those patients with a cough … ” “... Reversible taste disturbance is also not a serious problem. Rather, I am more worried about the side effects that may be caused by such problems as safety, ethical considerations, or other issues. For example, drugs containing restricted ingredients like Codeine are difficult to market…” We coud obviously discuss the wider meaning behind each sentence but, just to say, regarding the last sentence here: "For example, drugs containing restricted ingredients like Codeine are difficult to market…” this could be written in a number of ways, e.g. whether the issue is about whether Codeine is difficult to market or whether it is difficult to get Codeine into a market. I hope that helps. Sean :)