Between 4.5 and 3.8 billion years ago, the earth became so ______ that it was not clear whether the shape would last or not.
Judging from his _______ look, I know it is a very _____ situation to her.
-----Will you please help me to take care of my cat when I go out? ----- ________.
________with so much trouble,we failed to complete the task on time.
When it was his turn to deliver his speech,________,he walked towards the microphone.
In order to meet the demands they had to________production.