We are living a_____.[ ]
A. still
B. quiet
C. calm
D. silent
答案：C
. As there is less and less coal and oil, scientists are exploring new ways of making use of ______ energy, such as sunlight, wind and water for power and fuel.
A．primary
B．alternative
C．instant
D．Unique
呼吸机常见并发症（）
A.肺气漏
B.呼吸机相关性肺炎
C.慢性肺疾病
D.早产儿视网膜病（ROP）
E.肺出血
