Twenty million years ago, Idoho was not the dry place as it is now. ______, it was warm and damp, covered with thick forests.

Proper exercise is good for your health._____, too much is bad for it.

Progress so far has been very good.______，we are sure that the project will be completed on time.

Mr. Brook didn’t come back at the usual time last night. ______, he met some friends and stayed out until midnight.

From this day      , I will be more careful when crossing the street.