The nurse observes that a depressed client has bathed, is wearing a clean blouse and slacks, and has combed her hair. Which statement by the nurse would be most helpful for the client

A. "I like your blouse and slacks. "
B. "You look good today. "
C. "I’m glad you’re feeling better today. "
D. "I’m glad you combed your hair today. "

某中学研究性学习小组，驾船至金鸡湖中，他们用细线系住石块，并用弹簧测力计测出其重力为6.0N．然后把石块放入湖水中，弹簧测力计的示数为3.6N．当石块触及湖底时，他们在细线上水面处做一标记，并测出石块到标记处的线长为4.8m． (g=10N/kg，p水=1.0×10³kg/m³)求：

(1)在湖水中石块受到的浮力；

(2)湖水对此处湖底的压强；

(3)石块的体积

(4)石块的密度。