In accounting for long-term construction contracts, the percentage-of-completion method is preferable to the completed contract method when: （）

A. the contracts are of a relatively short duration (less than one year).

B. lack of dependable cost estimates cause forecasts to be doubtful.

C. estimates of the costs to complete and the extent of progress toward completion are reasonably dependable.

幼儿语言教育的特点有（）

A.积累性

B.渗透性

C.易行性

D.先天性