下列仪器中,常用物质分离的是
①容量瓶;②蒸馏烧瓶;③漏斗;④燃烧匙;⑤天平;⑥分液漏斗;⑦胶头滴管;⑧蒸发皿
A.①③⑤
B.②④⑦
C.①②⑥
D.②③⑥⑧
答案:D
什么是监理技术建议书?它有什么用?
A neutral equilibrium position for a vessel means that the metacenter is().
A.lower than the keel
B.at the same height as the center of gravity
C.exactly at midships
D.at the center of the waterplane area