真空预压法的膜下真空度应稳定地保持在( )以上。
A.600mmHg柱
B.650mmHg柱
C.700mmHg柱
D.750mmHg柱
参考答案:B
Scientific surveys conducted during the climbs ______that Mount Huandoy in Peru______ 6395 meters high
A.shown;is
B.showed;was
C.shows;was
D.showed;is
人参具有什么功效:()
A.清热泄火
B.补益气血
C.发散行气