I’m sorry, I forgot ______ my homework to school .
"Double click" means you click twice on the button of the _______ to start the program.
一How long has Tom _______ Nancy? 一I don’t know. And I even didn’t know they ______ .
The book _______ well. I’m afraid it _________ out.
The villagers used to______ drinking water from the river nearby, but now they spend two hours _______ to get it in the mountain because of the dry weather in Yunnan.
––Have you returned the book to the library _______? ––Yes, I have _________ returned it.