He ______ many books in the last few years. [ ]

A. wrote

B. has written

C. was writing

D. was writing

在建筑电气工程中，需要按防爆标准施工的具有爆炸和水灾危险环境的场所，主要是锅炉房和自备柴油发电机组的燃油或燃气供给运转室，以及燃料的小额储备室。其配管应按防爆要求执行。( )