Always remember to put such dangerous things as knives out of children’s ________.                                                                     (2011·四川，13)

Emergency line operators must always ________ calm and make sure that they get all the information they need to send help.

Famous physicists from all over the world came to the US to ______the 100th anniversary of Albert Einstein’s birth.

Progress has been very good so far．We are，_________, confident that the work will be completed as expected．

Will you see to ________ that the luggage is brought back?