The time and effort he has devoted during the past few years____ trees in that remote area is now considered to be of great value．

A．to plant

B．to planting

C．plant

D．planting

化学液体消毒法中的注意事项，下列哪些是正确的（）

A.物品消毒前应进行清洗

B.物品消毒前无需干燥处理

C.消毒物品必须全部浸入溶液中

D.中空物品腔内可留有气泡

E.有套管和轴节的物品必须拆卸