布伦德尔层在世界各大都市经常演奏（）全套奏鸣曲。
A.贝多芬
B.海顿
C.莫扎特
D.勃拉姆斯
参考答案：A
Against this deteriorating global background, the improvement in economic performance in a few developing regions in 1991 was especially noteworthy. ( )
A．determinating
B．tolerating
C．improving
D．worsening
硝化甘油炸药的冲击感度为（）
A.16％-32％
B.4%-12%
C.40%-50%
D.100%
