化学实验必须严格按照实验步骤和要求，正确、安全地进行操作．
取用固体药品要用____ 或____ ，如取用块状药品，应怎样操作？____ ；
给试管中液体加热，管口不能____ ；
熄灭火酒精灯应用____ ；
加热固体时，试管口应____ ，原因是____ ．

把一个图形绕着某一个点旋转____度，如果它能够与另一个图形____，那么就说这两个图形关于这个点对称，也称____。这个点叫做____，这两个图形中的对应点叫做关于中心的____。

语法填空

    I have great news to report. Yesterday I ____ (give) a higher position in my company with ____ (high) pay . I ____ (work) for my company for a number of years, and things have gone quite ____ (good). First, I helped my department increase sales last year. Before that, we only earned 150,000 dollars a year.  We have advertised and promoted our products at trade shows , on TV and in the newspaper , ____ brings about a good result. Our company has become better ____ (know) not only in our area but also in other cities. Now, more and more ____ (customer) are learning about us ; When you have satisfied customers, the news gets around. Besides increased sales, I've established ____ good working relationship with my colleagues. We recognize each other's abilities and respect each other's opinion. All my co-workers believe I have the ability ____ (lead) the department in the right direction. Therefore, I accepted the promotion and the pay raise, and I'll do my best for my company and for my customers in the future. I'm sure that we ____ (have) a bright future.

函数$f\left(x\right)=\frac{1}{\sqrt{x}}$的定义域是（　　）

探究题