11. I have heard Dang Thai Son_______ the piano. a. delivering b. tying c. playing d. discovering 12. The young teachers wanted a Foreign Language Teaching workshop _______ in Ho Chi Minh City. a. be organized b. be operated c. to be held d. to invent 13. _______able to take part in the international math contest two years from now, Son works very hard in his math class. a. In order to be b. Son can be c. Son has been d. So that he would be 14. Try_______ so many mistakes, your test paper will get high grade. a. not to make b. not decide c. leaving d. take care 15. Let me_______ from you soon. a. report b. hear c. finish d. sail 16. John is too stupid_______ understand this. a. to b. for c. at d. in 17. The wind is strong enough to ___________ the roof __________ . a. blow / off b. blow / to c. blow / through d. blow / of 18. My father is too tired to ______________ me___________ my homework. a. help / with b. help / from c. helped / with d. helping / to 19. John wanted Mary_______ him soon . a. from working b. serve c. to write d. telephone 20. I want to leave early ________________ . a. tomorrow morning b. morning tomorrow c. today morning d. yesterday morning