Although he knew little about the large amount of work done in the field, he succeeded ________ other more well - informed experimenters failed.
That Xiao Shenyang was elected_____model worker of May Day caused ____enthusiastic discussion in China.
----What do you know the _____ of are the pig influenza in humans? ---- usually similar to regular human seasonal influenza .
People go out with masks,________.
The dead rate is _____ pigs and recovery usually ______ within 7-10 days. A low in; occurs B.rich in;happens C.high in; came about D.poor in;took place
_____ three influenza type A virus subtypes(子类型) have been found in pigs.