下列是日本发动的侵华事变，其中标志着中国局部抗战开始的事件是（    ）

⑴Dad，where are my keys? ____         A．No，thanks．

⑵What's in your schoolbag?____         B．He's a doctor．

⑶Would you like a knife and fork?____   C．They are in the door．

⑷What's your father's job?____          D．Yes，they are．

⑸Who is she?____                      E．Two pencils and many books．

⑹Are they on the table?____            F．She's my aunt．

把西方进化论思想介绍到中国，指出中国只有实行变法维新，才能“自强保种”的是（　　）

﹣个瓶子装满水时的总质量是400g，装满酒精时的总质量是360g．则瓶子的容积是（ρ_水=1.0g/cm³，ρ_酒精=0.8g/cm³）（　　）

如图，将正在发声的小电铃放在连通于抽气机的密闭玻璃罩内，则：