高倍数泡沫灭火系统水泵入口前或压力水进入系统时应设管道过滤器,其网孔基本尺寸为()mm。
A、1.00
B、1.50
C、2.00
D、2.50
参考答案:C
近年来,全球地震频繁发生,对人类生产和生活造成严重破坏,读表2,回答27-29题。
小题1:表中所示三次地震中,智利地震造成的死亡人数最少。主要是因为
①震源较深 ②震级较小 ③发生在夜间 ④人口密度较小
A.①②
B.②③
C.③④
D.①④小题2:关于三地地震的叙述,正确的是
A.死亡人数与震级大小成正比
B.震源均位于上地幔的软流层中
C.三地所处地震带不相同
D.均位于美洲板块与太平洋板块交界处小题3:汶川地震发生时,在西江上的一艘渔船上人们感觉到
A.左右摇晃
B.上下颠簸
C.先左右摇晃,后上下颠簸
D.先上下颠簸,后左右摇晃
Directions: For each numbered blank in the following passage, fill in a suitable word in each blank on the ANSWER SHEET. What is meant (51) the word "friend" The dictionary (52) it as: "one attached to (53) by affection or esteem". Americans use the word freely -- that is, a friend may or may not be a person (54) whom there is a great attachment. A friend might be a casual acquaintance or an intimate companion. Friends may have known each other (55) childhood or they may have recently met. It is difficult to formulate a precise (56) of this word as it is used in the United States, (57) it cover many types of relationships. "My friend and I went to the show last night." "My friends gave me the name of a good doctor." "My friend consoled me when I was depressed." We hear such daily references (58) the word "friend" without knowing the quality of the friendship referred to. It is common for Americans to have different "circles of friends" such (59) church friends, work friends, or sports friends. A person may choose not to involve members of different circles (60) the same activity. (One’s friends from the office may never meet one’s friends from the sports club.) (61) such as "office mate" and "tennis partner" (62) the segregation of friends. The office mate is a friend in the office and the tennis partner is a friend (63) the courts. People have different types of friends: one may have many good friends and one best friend. "Best friends" are usually two people of the same sex who have known each other (64) a long period of time. People usually have more casual friends than close or best friends. Americans are geographically mobile and learn to (65) friendships easily and quickly. Approximately one (66) of every five American families moves every year. People relocate (67) they begin new jobs, (68) distant colleges, get married, have chidren or simply want a change in their lives. Perhaps as a consequence of this, people form and (69) friendships quickly. Students attending two or three universities during their undergraduate and graduate years may (70) their circles of friends several times.