With all the food supply ___, the researchers had to put an end to the wildlife protection project and returned home.

A．running out

B．to use up

C．run out of

D．using up

可用于制备不溶性骨架片的是（）。

A．羟丙基甲基纤维素 

B．单硬脂酸甘油酯 

C．大豆磷脂 

D．无毒聚氯乙烯 

E．乙基纤维素