题目

如图甲所示，一个柱形容器放在水平桌面上，容器中立放着一个底面积为100cm2 ， 高为12cm均匀实心长方体木块A，A的底部与容器底用一根细绳连在一起，现慢慢向容器中加水，当加入1.8kg的水时，木块A对容器底部的压力刚好为0，如图乙所示，此时容器中的水的深度为9cm．已知细绳长度为L=8cm，ρ水=1.0×103kg/m3 ． 求： （1）当木块A对容器底部的压力刚好为0，A受到的浮力；（2）木块A的密度；（3）若继续缓慢向容器中加水，当容器中的水的总质量为4.5kg时Sandra，Bill，Tommy and Sally are in the same class，but they like different（不同的）food．Here is a food list of their three meals（饭）．NameBreakfast（早饭）Lunch（午饭）DinnerSandramilkhamburgers，Coke，ice creamice creamBilleggs，milk，pearschicken，carrots，tomatoes，onions，melonsrice，pears，bananasTommyeggs，bananas，milkchicken，carrots，onionsonions，orangesSallyeggs，apples，milkchicken，carrots，noodlesbananas，ice cream小题1:The four students all have ________ for breakfast．A．eggsB．milkC．fruitD．vegetables小题2:________ eats some fruit for lunch．A．BillB．SallyC．SandraD．Tommy小题3:Tommy has ________ for dinner．A．meat and fruitB．ice creamC．meat and drinks D．fruit and vegetables小题4:What does the word“list”mean（意思是）in Chinese?A．价格B．说明C．清单D．单据小题5:Which of the following is TRUE?A．The girls like vegetables．B．Sally doesn’t eat chickenC．They all have fruit for dinner．D．Bill eats lots of fruit a day．