Make sure the gas is turned off after cooking, which would        cause danger to our life.

When you drive home, you can’t be＿＿＿＿＿＿＿careful. 

I ran across a car crash in Hong Kong, and ________, both sides just politely exchanged the telephone numbers and cards, a surprise to me.

Joe worked so hard that ________ he made himself ill.

 The price was _____ within the reach of the average household.