Which month has ______days in a year? —February.

Despite barriers and hardships，they ______ the research on cloning tissues.

The idea ________ good. We can try it.

Do you know the activity called “________ Lights” —Oh,it’s an activity that reminds people of saving energy.

__ is an unreasonable dislike of a particular group of people or things, or a preference for one group of people or things over another.