变频器运行中频率调节的方式有()。
A、本机给定、开环运行;
B、本机给定、闭环运行;
C、模拟给定、开环运行;
D、模拟给定、闭环运行。
参考答案:A, B, C, D
用所给单词的适当形式填空。
1. In 1809, Santa had eight ________ (reindeer).
2. Most animals run on four ________ (foot).
3. —What's your _______? —1.88m. (high)
4. Her grandfather told her not ________ (water) the flowers if it rained.
5. Our class could play soccer for a week without ________ (stop).
下列选项中,属于双方行政行为的是 ( )
A.行政征收
B.行政许可
C.行政给付
D.行政合同