$$\frac{1}{n(n+1)}$$-$$\frac{1}{(n+1)(n+2)}$$=$$\frac{2}{n(n+1)(n+2)}$$.$$\frac{2*29}{5*6*7}$$+$$\frac{2*29}{6*7*8}$$+$$\frac{2*29}{7*8*9}$$+......+$$\frac{2*29}{28*29*30}$$=?
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A$$\frac{14}{15}$$
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B$$\frac{17}{15}$$
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C$$\frac{22}{15}$$
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D$$\frac{26}{15}$$
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E$$\frac{28}{15}$$
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正确答案: E