平凡píng fán
commonplace, ordinary, mediocre平坦píng tǎn
level, even, smooth, flat幼稚yòu zhì
young, childish, naive庄重zhuāng zhòng
grave, solemn, dignified庞大páng dà
huge, enormous, tremendous开明kāi míng
enlightened, open-minded开朗kāi lǎng
spacious and well-lit, open and clear开阔kāi kuò
wide, open (spaces), to open up