1 . By the time you come back next year, the new house ________ (build) with the workers’ joint efforts.（所给词的适当形式填空）

2 . All the business letters ________(answer) by tomorrow. (所给词的适当形式填空)

3 . As many as ten million children ________ (infect) with the virus by the end of the decade. (所给词的适当形式填空）