82. He cleaned the glasses Carefully __________________ (以免它被弄壞了而變得不保暖).
83. Before each text our teacher will have a detailed explanation, which will _______________ (使文章易于學(xué)生理解).
84. This is a revision paper. When you do it, __________________ (你最好在你有問題的地方做個(gè)標(biāo)記).
85. We were all surprised __________________ (當(dāng)他宣布馬上要辭職時(shí)).
86. We are happy that ________________(這次實(shí)驗(yàn)比預(yù)想的要簡單得多).