The doctor advised me              the medicine three times a day. [ ]

A. to take

B. take

C. taking

D. to taking

利用浓硫酸配制一定量的质量分数为20%的稀硫酸，正确的操作步骤是 [ ]

A. 计算--称量--溶解

B. 称量--计算--溶解

C. 量取--计算--稀释

D. 计算--量取--稀释