(A) 条件(1)充分，但条件(2)不充分．
(B) 条件(2)充分，但条件(1)不充分．
(C) 条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
(D) 条件(1)充分，条件(2)也充分．
(E) 条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．
Todd’s construction company is capable of building 40 houses a year. Todd’s brother Mike also owns a construction company. How long does it take the two companies together to build 64 houses
(1) Mike’s construction company is capable of building houses twice as fast as Todd’s company does.
(2) Mike’s construction company is capable of building 20 houses every three months.
