A：me
B：girl
C：boy
读旅游计划卡片，回答下列问题。
Who: The Chens
Where to go: Shanghai
When: May Day Holiday
Go there by: plane
How long: three days
Stay in: a Four-star hotel
Activities: go to Yu Garden,
taste roast goose
如图所示，电源电压是5V并保持不变，开关S闭合后电压表的示数为3V，则（ ）
，
，则
