Being a parent is not always easy, and being the parent of a child with special needs often carries with ___ extra stress.  

 --- Which of the two subjects do you like, art or music?---_______ . They are really interesting.

— How many of your class will go to the park? -- _________ .

 _______ worries the public a lot the way the students are getting more and more stressed out.

The threats to the health of astronauts in space are very different from ______ on earth.