. Mother has been busy packing my belong

The farmers ________ on the farm when a UFO flew over their heads. [ ]

A. worked

B. work

C. fire working

D. were working

巨大儿是指胎儿体重（）

A.大于3500g

B.达到或超过4000g

C.超过4500g

D.达到或超过4500g

E.超过4000g

吞噬细胞将侵入人体的病原体吞噬消化属于特异性免疫．______．

金黄色葡萄球菌引起化脓性感染的特点是（）

A.病灶易局限

B.病灶易扩散

C.可引起局部及全身化脓性炎症

D.可通过多途径侵入机体

E.脓汁黏稠

中国最早的官办学府是（）在位期间设立的（）。