1．— Wha t do you think of the grammar book?
— Oh, it really is ________ useful reference book, which is worth reading ________ second time.
A. a; a B. an; the C. an; a D. the; the
2. －When will the game begin?
－It will begin later than usual __________ 15 minutes.
A. in B. on C. by D. at
3. Hearing his words, I couldn’t decide ___________ or remain.
A. whether to go abroad B. if I go abroad
C. if to go abroad D. to go abroad
4. This is the book I bought yesterday, _______ I spent 8 yuan.
A. on which B. for which
C. in which D. at which
5. All the employees except the manager ______to work online at home.
A. encourages B. encourage C. is encouraged D. are encouraged
