下列名胜古迹不在北京的是
A:明清故宫
B:颐和园
C:天坛
D:承德避暑山庄
往水面上浮的“气泡”
悬浮在水中的潜水艇 浮力<重力
浮在水面上不动的枯木枝 浮力=重力
往水底下沉的葡萄 浮力>重力
沉在水底的小石块
I often go online and use the computer doing my homework.____
Jenny's uncle is a scientist. She is proud ________ him.