油砂主要分布在（）。
A.北美洲
B.非洲
C.中亚
D.俄罗斯
参考答案：A, B, C, D
She opened her eyes with a start and was about to cry out ________ she heard her father urgently telling her to keep quiet.
A．while
B．before
C．when
D．as
结合北京故宫太和殿谈清代木构架建筑的造型特点
