反跳痛的发生机理是
A.腹腔内有关炎症病灶 B.腹膜的壁层受炎症累及 C.腹腔内有出血D.腹膜的脏层受炎症累及 E.胃或肠穿孔
参考答案:B
Life in cities is much livelier than ________ in the country.
A./
B.that
C.it
D.the one
四等水准测量某测站后视黑面上丝读数为1213,下丝读数为0785,中丝读数为0999,则该测站对应的后视距为()m。