【单选题】Read the paragraph from the section "Winning A Twitter Challenge." Eric's father is a federal worker. He works for the U.S. government. He had been forced to take a leave of absence, like an unwanted ...
【简答题】数列{a n }满足a 1 =1, ,其中λ∈R,n=1, 2,…,给出下列命题: ① λ∈R,对于任意i∈N*,a i >0; ② λ∈R,对于任意i≥2(i∈N*),a i a i+1 <0; ③ λ∈R,m∈N*,当i>m(i∈N*)时总有a i <0。 其中正确的命题是( )。(写出所有正确命题的序号)
【单选题】Read the paragraph from the section "Winning Peanut Butter Forever." Eric's father is a federal worker. He works for the U.S. government. He has been forced to take a leave of absence. He cannot go to...