I have a big family. My name is Tony Brown. I'm English. My father and mother are teachers. They teach (教) English in No.1 Middle School. I have a sister. Her name is Mona. We are students in N0.1 Middle School. My grandfather's name is David, My grandmother's name is Sue. They are retired (退休的), they are at home. Paul is my uncle. He is a worker (工人). Paul's wife (妻子)—Jane, is a doctor (医生). They have a son. His name is Jeff. He's only three.

已知a、b、c三种物质的溶解度曲线如图1，根据题意回答下列问题．

（1）下列说法中，正确的是____ ．

A．a与b相比，a的溶解度大于b的溶解度

B．在t₁℃时，a与b的溶解度相等

C．t₂℃时，将30g a物质溶于50g溶剂中，可得到80g溶液

D．从t₂℃降温至t₁℃时，c有晶体析出

（2）如图2所示，将盛有c物质饱和溶液的试管置于盛有适量水的烧杯中，需向烧杯内加入下列哪种物质，才能使试管内的饱和溶液变为不饱和溶液____ 

A．浓H₂SO₄   B．氢氧化钠    C．蔗糖    D．食盐    E．硝酸铵．