表示两个比( )的式子叫做比例。用12的4个因数组成一个比例是( )。
相等;3:1=12:4(答案不唯一)
“帮助”为用户提供使用Windows XP时的帮助信息。( )
Lifeboat hatchets should be().
A.kept in a locker
B.secured at each end of the boat with a lanyard
C.kept next to the boat coxswain
D.kept in the emergency locker on the ship and brought to the lifeboat when needed