The nurse teaches a mother how to provide adequate nutrition for her toddler, who has cerebral palsy. Which of the following observations indicates that teaching has been effective ？（）

A．The toddler stays neat while eating.

B．The toddler finishes the meal within a specified period of time.

C．The child lies down to rest after eating.

D．The child eats finger foods by himself.

乙炔瓶内气体溶解于（）中，气瓶在使用时应直立放置。

A、丙酮

B、水

C、乙醇

D、甲醇