A boy with two dogs _______ when the earthquake happened. [ ]

A. were sleeping

B. were asleep

C. was sleeping

D. fell asleep

冷冻干燥制品的正确制备过程是

A．测定产品共熔点→干燥→预冻→升华再干燥
B．预冻→升华干燥→测定产品共熔点→再干燥
C．测定产品共熔点→预冻→升华干燥→再干燥
D．测定产品共熔点→升华干燥→预冻→再干燥
E．预冻→测定产品共熔点→升华干燥→再干燥