主动语态与被动语态相互转换，每空一词(含缩写)。
1.Wecallmathsthelanguageofscience.(改为被动句)
Maths__________________thelanguageofscience.
2.Wheredidtheyplanttrees?(改为被动句)
Where_________trees_________?
3.Youcanborrowtwobooksatatime.(改为被动句)
Twobooks___________________________atatime.
4.Theteachermadethestudentscopythetext.改为被动句
Thestudents___________________________copythetext.
5.TheyproducesilkinSuzhou.(改为被动句)
Silk__________________inSuzhou.
6.Theybuiltabridgebetweenthetwoislandslastyear.(改为被动句)
Abridge________________betweenthetwoislandslastyear.
7.Abirthdaypartywillbegiventomorrow.(改为主动句)
We__________________abirthdaypartytomorrow.