例句與造句

1. if medication is necessary, be sure to strictly follow instructions on dosage and complete the whole course . at present there is no vaccination or prophylactic medications effective against dengue fever
   由于目前并無有效預(yù)防登革熱的藥物或疫苗，所以當(dāng)身處外地時(shí)，以下的防蚊措施是不能忽視的：
2. for example, some african countries require that you take a yellow fever vaccination before entering the country, and that vaccination takes ten days to become effective . if you are visiting a country where malaria is prevalent, you may need to start taking prophylactic medication a week before departure, and continue taking it for another four weeks after you return home
   例如，部份非洲國家于入境前必須接受黃熱病疫苗注射，而該疫苗需時(shí)十天才能產(chǎn)生效用；而前往一些瘧疾盛行的地區(qū)，則可能需要在入境前一星期開始服食預(yù)防藥物，并在返港后四星期內(nèi)繼續(xù)服用。
3. It's difficult to find prophylactic medication in a sentence. 用prophylactic medication造句挺難的