—Why do many people keep dogs as pets?—Because they are our ____ friends and they never desert their masters.

.Wait till you are more ______. It’s better to be sure than sorry.

He visited the bookstore every week. He became such a____ customer that the bookseller gave him some books as presents.

—— What do you think of the concert? —— Oh, it was＿＿＿＿＿success. 

 With his wife talking endlessly about his this and that, it is quite _______ for him to lose his temper.