Thanks to _____ help from his teachers and classmates, he has made _______ rapid progress in his studies.

A．不填；a

B．the; 不填

C．the; a

D．a; the

采用干燥剂干燥法测定干燥失重的药物特点是

A．受热易分解

B．受热易挥发

C．含有水分量大

D．熔点低

E．易挥发性