例句與造句

1. The multivalent vaccines that i give puppies at 12 , 14 and 18 weeks of age contain attenuated ( weakened ) canine coronavirus
   同時多價疫苗一般在幼犬12 ， 14 ， 18周的時候進(jìn)行注射。
2. It's difficult to find multivalent vaccine in a sentence. 用multivalent vaccine造句挺難的