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phamquoctuan21022002
2 năm trước
Bài 1. Tính các tổng sau: a) S1 = 1 + (-2) + 3 + (-4) + … + (-2014) + 2015 b) S2 = (-2) + 4 + (-6) + 8 + … + (-2014) + 2016 c) S3 = 1 + (-3) + 5 + ( -7) + … + 2013 + ( -2015)
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III . Use the conjunctions ( but , and , so , although , or because ) to fill in each space . 1 . I don ' t go to school today . . . . . . . . . . . . . . I am ill . 2 . . . . . . . . . . . . . . . . . . . . . . . . . . it is raining hardly , they have go to work now . 3 . My close friend likes English very much . . . . . . . . . . . . . . . . . . . . . . she practices English every day . 4 . My sister . . . . . . . . . . . . I always help our mom tidy the house . 5 . It is a sunny . . . . . . . . . . . . . . . . . . . windy today . 6 . Some game shows are popular . . . . . . . . . . . . . . . . . . . . . . . . . . I never watch them . 7 . They cancelled their picnic . . . . . . . . . . the weather was bad . . . . . . . . . . . . . this exercise is very difficult , we try to do it . 8 . . . . . . . . . . . . this exercise is very difficult, we to do it

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