．Into the dark apartment ____ , who was quite surprised when everyone shouted “Happy Birthday”.
| A．did David walk | B．David walked | C．David did walk | D．walked David |
Susan advised me not to buy the vase, but I bought it _____.
| A．anyhow | B．however | C．though | D．Totally |
The two top students in Mr. Green’s class competed _____ each other for the highest marks.
| A．to | B．for | C．in | D．Against |
Everyone has periods in their lives________ everything seems very hard.
| A．when | B．where | C．which | D．That |
—How about camping this weekend，just for a change?
—OK，________you want.
| A．whichever | B．however | C．whatever | D．Whoever |
In _________to being used in industry，laser can be applied to operations in the hospital.
| A．devotion | B．addition |
| C．application | D．Reception |