They learned it all by themselves. That is to say nobody told them ________ .
| A．what to do it | B．how to do it | C．where to do | D．when to do |
--- Are there ___________ students in your school?
--- Yes, _____________ the students is about 2000.
| A．a number of; a number of | B．the number of; the number |
| C．a number of; the number of | D．the number of; a number of |
___________ it snows, ____________ the children feel.
| A．More heavily; the happier | B．More heavily; happier |
| C．The more heavily; happier | D．The more heavily; the happier |
Luo Yang devoted all his life _________for China Nation Aviation(中国航天).
| A．to work | B．work | C．to working | D．worked |
______ the age of 89, he passed away ______ a cold winter morning.
| A．At, on | B．On, on | C．At, in | D．In, on |