第三节：单句改错（每小题1分，满分5分）

在错的词下划一横线，在该行右边横线上写出改正后的词(每句均有一个错误)。

81. What the earth travels around the sun is known to us all.                              81. _______

82. The ruler that he bought yesterday was lain on the table.                             82.________

83. He returned in the afternoon of his birthday.                                            83. ________

84. He spoke too rapidly that we couldn’t clearly understand him.                   84. _________

85. He shouldn’t have gone abroad, for I saw him in the part this morning.             85. _________

用4个边长是1厘米的正方形拼成一个大正方形，大正方形的周长是______厘米，如果拼成一个长方形，这个长方形的周长是______．