His proposal is very _____. We do not need any explanation.

What makes the space shuttle _____ is that it takes off like a rocket but lands like an airplane.

―Are you satisfied with what she has done?    ―Not a little. It can’t be ________.

When you are ______ about something, you are ______ to do whatever you can to get it．

The student became ______ the danger of smoking and decided to give it up.