The insect ______ a powerful drug which affects mosquitoes. 

As there was no spare bedroom, Susan had to ______ her friend for a night in the sitting-room.

--Which color do you prefer, red or black? ---Red. For red_____a sense of energy and strength.

If you say that some people are selfless, you agree because they ______ other people more than themselves.

-----Thank you for the great favor you _____me in face of difficulty. -----It is no ______at all. Helping others also benefit me .