用推拉注射器活塞的方法可以检查下图装置的气密性．当缓慢拉动活塞时，如果装置气密性良好，则能观察到（   ）

被评为“四川省孝心少年”、“资阳市十佳美德少年”的叶富源（简阳市三岔中学高二学生）—背着父亲去上学的事迹撼动了众人的心灵。上述事件说明（  ）
①一个人应该学会承担责任，做一个负责任的公民 ②承担责任往往伴随着获得回报的权利 ③承担责任与否，取决于我们的自愿选择 ④我们应进一步弘扬中华传统美德  

用来擦拭显微镜头污点的是（  ）

Dear Grace,
    How are you? Thank you for your last e-mail. You want to know about my school clubs, right ? Well, it's time for us to join the school clubs now. There are many clubs in my school, like the English club, the art club, the music club and the sports club. I have two good friends, Jack and Lisa. We all want to join the school clubs.
    I want to join the music club, because I can play the guitar. I can't speak English well, but I also want to join the English club.
Jack likes sports. He can play soccer and basketball. He is in the school soccer team(队). He wants to join the sports club. He can play the guitar, too. But he doesn't want to join the music club.
    Lisa likes drawing. She wants to join the art club. She also speaks English very well. I think she can be in the English club. But she can't be in the music club. She can't play any instruments(乐器).
    Are there any clubs in your school? What club are you in? Please write an e—mail and tell me about your school clubs.
Yours,
Jane

僧肇说：“旋岚偃岳而常静，江河竞注而不流，野马飘鼓而不动，日月历天而不周。复何怪哉？”下列观点中与其错误相近的是