The main cause of HIV / AIDS infection in China is drug abuse, ______ is very serious in Yunnan.
| A．what | B．who | C．that | D．which |
Drivers should be especially careful near schools, where there are _____ to be many children.
| A．possibly | B．probably | C．likely | D．seemly |
______ is obvious to the students that they should get well prepared for their future.
| A．It | B．What | C．That | D．This |
The ‘how-to’ book can be of use to wants to do the job.
| A．who | B．wha t |
C．whoever | D．whatever |
. ______ we are sure about is the need to prevent children from being spoiled.
| A．What | B．Which | C．Whether | D．That |
. I was wondering what it is _____ has made her so popular with her workmates.
| A．that | B．which | C．how | D．who |