撒哈拉以南的非洲是矿产资源宝库,____ 、____ 的储量和产量均居世界首位.
用所给词的适当形式填空。(1)What’s your____ (high)?(2)The boys often go____ (swim) in that river in summer.(3)Nobody ____ (like) his new look.(4)Many young people want to be____ (sing).(5)He wears____ (glass) every day. He thinks that’s very cool.
在四边形ABCD中,∠B=90°,AC=4,AB∥CD,DH垂直平分AC,点H为垂足,设AB=x,AD=y,则y关于x的函数关系用图象大致可以表示为( )