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I like to play basketball, _______ she likes to play ping-pong.
1年前
用括号内动词的适当形式填空____ you ____(write) a letter to your mother at the moment?
1年前
This is the factory. He worked in the factory 10 years ago.(用定语从句改写)
1年前
1年前
已知{an}是等比数列,a1=3,a4=24,数列{bn}满足:b1=0,bn+b(n+1)=an, (1)求证an=3×2^n-1; (2)求证:bn=2^(n-1)+(-1)^n.
1年前