The second question:

The third question:

The fourth question:

This part of the extended information mainly examines the knowledge points of the past perfect continuous tense and the future perfect continuous tense:

For the past, it means that the action lasts from a certain time in the past to a certain time in the future. Whether the action will continue depends on the context. The past and future perfect continuous forms are composed of should/would be+v-ing; The negative form should/should+not+always+v-ing; The problem form is to push should/wow.

Modal meaning of past and future perfect continuous tense, the structure of "would have+present participle" is not only used to express past and future perfect continuous tense, but sometimes it may be a modal verb with modal meaning, and comparison indicates speculation or conjecture.

For example, "What interesting job did you find?" Helen asked him; He knew she would be thinking about it all the time. "What interesting job did you find?" Helen asked him. He knew that Helen would always think about it.