正常人精神紧张时可引起 A.
收缩压、舒张压升高 B.
收缩压、舒张压均无变化 C.
收缩压升高，舒张压无明显变化 D.
收缩压降低、舒张压升高 E.
收缩压无明显变化，舒张压升高

单项选择题二里头文化跟以下哪个朝代有关 A、商 B、夏 C、周 D、秦

单项选择题Jack was distant, unfriendly at best, and then he even ________ pulled out a textbook and started to read it, blocking us out completely. A、abruptly B、anticipatedly C、prudently D、recklessly