第15题: [单项选择]The greatest outcome of the discovery of the reaction principle was that
A rockets could be propelled into the air.
B space travel became a reality.
C a major problem had been solved.
D bigger rockets were able to be built. 参考答案:B
第16题: [单项选择]新生儿肺透明膜病最主要见于 A. 巨大儿 B. 早产儿 C. 足月儿 D. 急产儿 E. 窒息 参考答案:B