;Ⅰ.在空白处填入括号内单词的正确形式

1.Everymeans_________(be)trieduptonow,butwestillcantcomeupwithagoodwaytohandlethecurrentdilemma.;2.Myeldersistershairis__________(two)thelengthofmine.;3.Atpresent,__________(billion)ofpeoplelivewithoutsufficientshelterandcleanwater.;