现在我们将做一批练习，在练习的过程中你需要键入程式码，并且让它们运行起来，我不会解释太多，因为这节的内容都是以前熟悉的。这节练习的目的是巩固你学到的东西，我们几轮练习后再见。不要跳过这些习题，不要复制贴上！
puts "Mary had a little lamb."
puts "Its fleece was white as %s." % 'snow'
puts "And everywhere that Mary went."
puts "." * 10 # what'd that do?
end1 = "C"
end2 = "h"
end3 = "e"
end4 = "e"
end5 = "s"
end6 = "e"
end7 = "B"
end8 = "u"
end9 = "r"
end10 = "g"
end11 = "e"
end12 = "r"
# notice how we are using print instead of puts here. change it to puts
# and see what happens.
print end1 + end2 + end3 + end4 + end5 + end6
print end7 + end8 + end9 + end10 + end11 + end12
# this just is polite use of the terminal, try removing it
puts$ ruby ex7.rb
Mary had a little lamb.
Its fleece was white as snow.
And everywhere that Mary went.
..........
CheeseBurger
$接下来几节的加分习题是一样的。