Unit 4 Astronomy: the science of the stars(Period 1　Warming up and reading)

1) what it was to become was uncertain until between 4. 5 and 3. 8 billion years ago when the dust settled into a solid globe.2) the earth became so violent that it was not clear whether the shape would last or not.3) they were in time to produce carbon, nitrogen, water vapor and other gases, which were to make the earth’s atmosphere.4) so whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.suggested explanations:1) what leads a noun clause as the subject and when leads an attributive clause.2) here “whether the shape would last or not” is a noun clause as the subject.3) here “which were to make the earth’s atmosphere” is a non-restrictive attributive clause.in time: 1) sooner or later; eventually 2) in time (for sth. /to do sth. ): not latei will see him in time.she will be back in time to prepare dinner.4) in this sentence, there are two clauses led by whether. the first one is a noun clause as the subject and the second as the object.to come: serves as attributiveshe is the last person to do such a thing.depend on: something might only happen or be true if the circumstances are right for itour success depends on whether everyone works hard or not.5. reading aloud and underliningask students to read the passage aloud to the tape and let them pay attention to the pronunciation of each new word and the pauses within each sentence. tell them to pick out all the useful expressions or collocations from the passage while reading and copy them to the notebooks after class as homework.collocations: on the earth, according to, a cloud of dust, so. . . that, whether. . . or not, in time, water vapor, cool down, on one’s surface, allow. . . to do. . . , a chain reaction, millions of, on the surface of, be able to, as well as, by doing. . . . , lay eggs, be different from, give birth to, spread all over the earth, in one’s turn, prevent. . . from, as a result of, too. . . to. . . , depend on→step 5 discussionafter reading the passage, let students discuss the following questions.1. why do you think that humans are the cleverest animals on the earth?2. do you believe that there is life on other planets? why or why not?3. do you think it is possible that one day people will move their houses to other planets?→step 6 consolidationask students to retell the passage with the help of the following.a cloud of dust→a solid ball→presence of water→small plants grow on the water→shellfish and other fish appear→plants begin to grow on dry land→insects and amphibians appear→retiles appear→dinosaurs appear→mammals appear