This was an infrequent , but very possible case.
这是一种罕见，但很可能的情况。
Rubella is an important childhood disease that was historically widespread but is now very infrequent .
风疹是儿童期疾病中重要一员，在既往很流行，但现在发作很少。
Rubella is an important childhood disease that was historically widespread but is now very infrequent .
风疹是儿童期疾病中重要一员，在既往很流行，但现在发作很少。
应用推荐