He found it hard for Alan to focus on his teachers for longer than five minutes, _________ if the lecture was boring. 

I _____ watch foreign movies in my spare time ，but I appreciate Chinese ones occasionally at home.

—Must I turn off the gas after cooking?—Of course.You can never be ________ careful with that.

 After years of changing residence (住处) and promotion, Madelyn moved to a new city and _____ became vice-president of a local bank.

We have saved some money,but it’s __________ not enough to buy a new house.