在电子点火系统中,点火提前角由()决定。
A.蓄电池电压和发动机水温
B.使用汽油的牌号
C.发动机转速和发动机负荷大小
D.以上三者均是
参考答案:C
It was quite emergent.The small boat and its staff were at the _____ of the rough sea. [ ]
A.kindness
B.sympathy
C.mercy
D.heart
()是健美操的灵魂。
A.音乐
B.舞蹈
C.操化动作
D.难度动作