(____)I don't know.
(____)Where is my pencil?
(____)Li Hua, Where's your pencil?
(____)There it is.
(____)Danny, where is my pencil? Can you see it?(你看见它了吗?)
心脏中血液的流向是( )
长白山地主要的经济活动是( )
①5mL量筒 ②10mL量筒 ③20mL量筒 ④胶头滴管.