雾化蒸汽压力过小的现象().
A、不能很好地雾化燃料油
B、燃料油不能完全燃烧
C、火焰软而无力,呈棕色,烟囱冒黑烟
D、燃烧道及火嘴口容易结焦。
参考答案:A, B, D
— How about your travel?
— You can hardly imagine what difficulty we have had ______ the vast desert. [ ]
A. explored
B. exploring
C. to explore
D. explore
我国的最高立法机构?