All the scientific evidence ___ that increasing use of chemicals in farming ____ damaging our health. A. show; are B. shows; are C. shows; is
When the flood was washing the village, people screamed and ran all directions. A. in fear, with B. with fear, in C. in fear, in D. with fear , with
A new report says only about half of all students in the main school systems of America’s largest cities finish high school. The report notes higher rates of graduation — over 70% —in areas su
30．梭伦在抒情诗中表达了实行民主改革的原则：“我所给予平民的适可而止，他们的荣誉不减损也不增多；即使是对那些有财有势的人也一样，我不使
如图甲所示是一个用折射率n=2．4的透明介质做成的四棱柱的镜截面图。其中∠A=∠C=90°，∠B=60°。现有一条光线从图中所示的位置垂直入射到棱镜的AB面
下列离子方程式书写正确的是( ) A. FeCl3溶液腐蚀印刷电路铜板：Cu＋Fe3＋===Cu2＋＋Fe2＋ B．醋酸溶解鸡蛋壳：2H＋＋CaCO3===Ca2＋＋CO2↑＋H2O C．在NaHSO4溶液
去冬今春以来，由于干旱少雨，我国多个地区发生了森林火灾，防火形势十分严重。近期在某地发生的山火中，部队及时出动直升机进行扑救，有效地
电路中形成电流的条件是（ ） A．电路两端要有电压 B．电路是闭合的 C．电路两端既要有电压，且电路又是闭合的 D．
