卷材屋面的防水功能要求主要是（），保持卷材与基层的粘结。
参考答案：耐久性、耐热性、耐重复伸缩、保持卷材防水层的整体性
________a pianist, I had to sing solo. Much to my relief, my performance was fully appreciated by
the audience. [ ]
A. Lack
B. Lacking of
C. Lacking
D. Lacked in
