根据句意，用括号中所给单词的正确形式填空。

小题1:All the homeless children               (look) after well.

小题2:I’m not               (certainly) whether I can do it.

小题3:We have decided not to go, though it was difficult               (decide).

小题4:I’ve two               (knife). I use them to cut watermelons.

小题5:When I visited them last night, they               (chat) by the fire.

下列属于自动低频减负荷装置的整定原则的有（）。

A.自动低频减负荷装置动作，应确保全网及解列后的局部网频率恢复到规定范围内

B.自动低频减负荷装置动作，应使系统功率缺额造成频率下降不应使大机组低频保护动作

C.自动低频减负荷顺序应次要负荷先切除，较重要的负荷后切除

D.自动低频减负荷顺序应重要负荷先切除，次要的负荷后切除