An advantage of being the youngest child in his family is __________he gets a lot of attention.
| A．that | B．whether | C．why | D．when |
15. Researchers _______ to develop vaccines and this will probably take several months to complete.
| A．are working | B．worked | C．will work | D．has worked |
14. Water can absorb and give off a lot of heat, thus ________ a stable environment.
| A．creating | B．to creat | C．created | D．being created |
13. He took ________ advantage of cultural resouces and succeeded in ________ 1990s.
| A．an ; / | B．the ; the | C．an ; the | D．/ ; the |
12. I'm _______ in studying English words. Don't bother me
| A．absorbing | B．absorbed | C．to absorb | D．being absorbed |
11. --- Don’t you know our boss accepted the suggestion _______ by some workers?
--- Really? That’s great.
| A．put off | B．put together | C．put forward | D．put aside |