简述幅度调制，列出两种幅度调制的名称。
纳税人开户银行对其开具电子付款凭证的真实性、有效性（）负责。 公开性。 长期性。 完整性。 及时性。
请将图中字母代表的地区与相应的气温降水图进行匹配。
单位时间内实际发出的交流电的电能叫有功功率。（）
When the incinerator is stopped, which of the following is wrong?（） After stopping supplying sludge oil, the value and pipe should be flushed by flushed by diesel oil and the incinerator continue burning for 10 minutes。 Close auxiliary burner firstly and then close main burner。 After stopping fuel, restoring the position of main fuel supply valve。 Stop blower as soon as stopping supplying fuel oil。
All marine low-speed diesels are of what design?（）
