巴洛克时期的肖姆管是（）的前身。
A.双簧管
B.横笛
C.单簧管
D.军笛
参考答案：A
下列用于抗心律失常的药物是
A．非诺贝特B．氨力农C．硝酸异山梨醇酯D．盐酸美西律E．双嘧达莫
With a lot of difficult problems () , the manager felt worried all the time.
A. settled
B. to be settled
C. settling
D. to settle
