stamps are used - sending letters

Stamps are used for sending letters.对sending letters提问 Stamps are used ————sending letters选择题A,by B,for C,with D,to Stamps can be used ______ letters.A.as B.to sending C.but D. 把下列句子变成被动语态:People use stamps for sending letters. stamps are used for_____(post）the letter 英语翻译if you are sending your letters far away,write on the en What two letters are also used as words? the s___ are used by people for sending and receving message 2.16Satellites are used by people for sending and to receive Jane said she __ sending e-mails ___ letters. Stamps______(use) for sending letters before.But now people These are China stamps.