湿法制颗粒压片时,干颗粒中20~30目的粉粒应控制在()
A.5%以下
B.5%~10%
C.10%~20%
D.20%~40%
E.40%~60%
参考答案:D
What worried the child most was ____to visit his mother in the hospital .
A.his not allowing
B.his not being allowed
C.his being not allowed
D.having not been allowed
A.听诊器能使振动的振幅增大,响度增大
B.听诊器能改变发声体的频率,使音调变高
C.听诊器能减小声音的分散,传入人耳的响度更大些
D.听诊器能缩短听者到发声体的距离,使传入人耳的响度更大些