Researchers in the country say they have developed a bird flu vaccine for human use , and the vaccine is " safe " and " effective " 中国研究人员声称已经研发出人用禽流感疫苗，而且这个疫苗安全有效。
Researchers in the country say they have developed a bird flu vaccine for human use , and the vaccine is " safe " and " effective " 国家研究人员说，他们已经研发了一种适合人用的安全有效的禽流感疫苗。
Researchers in the country say they have developed a bird flu vaccine for human use , and the vaccine is " safe " and " effective " 研究者说他们已经研制出一种人用禽流感疫苗，这种疫苗是安全和有效的。
Researchers in the country say they have developed a bird flu vaccine for human use , and the vaccine is " safe " and " effective " 中国研究人员表示，他们研制出人禽流感疫苗，并且这一疫苗安全而有效的。
Never do i hear anyone remind us of the fact that it is possible to go throughout the year without a flu vaccine and not get the flu 天，我从没有听过有人说：不必注射疫苗，也能整年都感染不到流感。
Researchers in the country say they have developed a bird flu vaccine for human use , and the vaccine is " safe " and " effective " 中国的研究人员说，他们研制出了人用禽流感疫苗，而且该疫苗安全且有效。
Researchers in the country say they have developed a bird flu vaccine for human use , and the vaccine is " safe " and " effective " 该国研究者说他们研制出一种人用禽流感疫苗，并且这种疫苗是安全有效的。
Researchers in the country say they have developed a bird flu vaccine for human use , and the vaccine is " safe " and " effective " 中国研究人员称他们已经研制出人用禽流感疫苗，而且这种疫苗是安全有效的。
Researchers in the country say they have developed a bird flu vaccine for human use , and the vaccine is " safe " and " effective " 研究人员表示他们已经研制出人用禽流感疫苗，并称该疫苗“安全” ， “有效” 。
Researchers in the country say they have developed a bird flu vaccine for human use , and the vaccine is " safe " and " effective " 该国研究人员表示他们已经开发出一种人用禽流感疫苗，这种疫苗是安全且有效的。
