With so many orphans _______, the charity organization calls for more donations.

A．to look after

B．being looked after

C．to be looked after

D．looked after

瓷全冠的耐磨性优于

A．纯金铸造冠

B．钴铬合金铸造冠

C．贱金属烤瓷冠

D．硬质树脂冠

E．贵金属烤瓷冠