观察岩石的外观并根据其外观特征,属于岩浆岩的有____ ,判断的依据是____ 。
将标有“6V,9W”灯L和电阻R按如图所示电路连接.已知电源电压为6V,当闭合开关S时,电流表示数是2.25A.
关于人体特异性免疫的叙述正确的是( )
— Would you like to go shopping with me now?
— Sorry, I have to finish my homework before supper.