——I am going to Qingdao and stay there for a week.
——______ you are there, would you please buy some books for me?
A:If
B:While
C:Since
D:As soon as
读图,完成下列要求:
选择“绝”字在词语“伯牙绝弦”中最正确的解释是( )。
下列物体中,既有动能又有势能的是( )