(2013·新课标全国卷Ⅰ) Try not to cough more than you can ________ since it may cause problems to your lungs.
For her, happiness ________ helping those in trouble.
I suggested that he _____ the manager before he decided.
His failure in the experiment suggested that he ________ his teacher’s proper instructions.
Professor Hawking stepped into the office I knew that there was no hope.
Usually children are allowed to ___________ when they are six years old.