患者发生呕血时，常提示一次上消化道出血量达到

A．50毫升以上

B．100毫升以上

C．300毫升以上

D．5000毫升以上

E．1000毫升以上

She longed for a pleasant trip in the summer, while her parents desired that she_______ at home, preparing for the coming exam..

A．stay

B．stays

C．must stay

D．would stay