It _____ that Yu Mei has changed a lot. [ ]
A. seem
B. seems
C. look
D seemed
答案:B
引起血小板输注无效的最多见原因是()。
液压支架安全阀开启时,表明支架在()阶段工作。
A、初撑
B、恒阻
C、承载
D、支撑