混凝土振捣采用插入式振动器的振捣顺序宜从近模板处开始,先外后内,移动间距不应大于振动器有效半径的()倍。
A.1
B.1.5
C.2
D.3
参考答案:B
将一定量的CO2通入下列溶液中,一定变浑浊的是
A.CaCl2溶液
B.澄清石灰水
C.饱和Na2CO3溶液
D.稀H2SO4
Passage 2
Which of the following diseases occurs more frequently in among Americans than in Britons as it is suggested Dr Marmot’s research a. Heavy drinking. b. Cancer. c. Heart disease. d. Insomnia.