It is important to have your eyes examined regularly to check for any sign of eye disease that may not have any ________.                                      (2012·湖北，29)

It’s a rule for all the students to ____ their places ahead of 5 minutes waiting for the class to be started.

 Eating too much fat can _____heart disease and cause high blood pressure.

As the price is rising, $100 a month can hardly _____ the cost of his life in such a big city.

Many interesting activities will be _____ in the summer camp to attract children .