31. It’s not easy for experts to ______ H1N1 flu in humans from regular human seasonal influenza.
| A．distinguish | B．separate | C．define | D．recognize |
Jane is ill and Annie is going to _______ this week.
| A．take place | B．take her place |
| C．take the place | D．be replaced |
If Penicillin had not been available, many people _______ from sickness or even small wounds.
| A．had died | B．have died |
| C．would have died | D．should have died |
_______strong evidence ______reading is beneficial to one’s success.
| A．It is；what | B．It is；that |
| C．There is；which | D．There is；that |
Teddy looked _____ at his broken model plane and felt ________.
| A．sadly; sadly | B．sad；sadly |
| C．sadly; sad | D．sad；sad |
_________the text messages we received always seem important at the time, most people can’t really remember them the next day.
| A．While | B．When | C．If | D．Since |