There's __________ with your computer. You'd better __________ as soon as possible.
A:wrong something; have it repair
B:nothing wrong; have it repaired
C:something wrong; have it repaired
D:something wrong; have it repair
电动自行车的电池能反复充放电使用,既节约了资源,也保护了环境.电池充电时,电能转化为 ____能,骑行时,将电能转化为 ____能.
Mary, the girl, is from England.
小明体重500N,周末他去“六盘水市游泳馆”游泳,当他套着游泳圈漂浮在2m深水区休息时(游泳圈的重量忽略不计),他所受的浮力为 ____ N,此时由于不小心,手牌滑落,沉到池底,则手牌受到的液体压强为 ____ Pa.然后他潜入水中老手牌,从他完全潜入到捞到手牌的过程中,他受到的浮力____ (选填“变大”、“变小”或“不变”).小明捞到手牌后,若他受到的浮力等于500N,在不做任何动作的情况下,他将在水中____ (选填“上浮”、“下沉”或“悬浮”).