一圆柱形闸门,长l=10 m,直径D=4 m,上游水深h1=4 m,下游水深h2=2 m,求作用在该闸门上的静水总压力的大小与方向为（）https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/c9bf93831c184ca6bcb8c0fa3bcbad78.png

设D：全总个体域，F(x)：x是兔子，G(y)：y是乌龟，H(x, y)：x比y跑得快。则命题“并不是所有的兔子都比乌龟跑得快”的逻辑符号化为（ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/4bf8891b2d6d48a588928ad6f1a11f46.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/405b0750d62148f29762b2dc436abdc9.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/f6a0186c98564711b88c7131613565b4.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/bbb70672339d498099c2a685f51ea16a.png" />

如图所示,宽b=1 m的矩形闸门,下端用铰链固定,上端用钩子支撑,左侧水深h1=4 m,右侧水深h2=2 m,钩子离水面的距离a=0.5 m,则钩子和铰链所受的力F1和F2分别为（）https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/59775e2471fc43b89313d1cf4ef20135.png

若DpM¢=±0.2，初始浓度为c mol‧L-1的金属离子M能被等浓度的EDTA标准溶液准确滴定(|Et|£0.1%)的条件为（ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/33c9302962c34933b4b5815f152867a7.png"/> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/c00c0ec7848542fbb5bbd3d6877b704f.png"/> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/6700752bb87749a1abc50478ead98ee1.png"/> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/9820acf95f2543cd94adcb5a8f9b3f7e.png"/>

设D：全总个体域，F(x)：x是人，H(x, y)：x与y相同，L(x, y)：x与y一样高。则命题“任何两个不同的人都不一样高”的逻辑符号化为（ ） A: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/4b94c698d08f4a04b660d5b6efb30089.png" /> B: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/786309b3ecdd4425922f5494966fa07d.png" /> C: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/0a4682e71855487ea0a81c3c14185b0b.png" /> D: <img src="https://image.zhihuishu.com/zhs/onlineexam/ueditor/202002/7c7bc9a8ab404881aa4b2624a45e3575.png" />