The professor’s research finally proved to be ______, though he had spent a lot of money on it.
| A．priceless | B．valuable | C．worthless | D．worthwhile |
According to the national population survey concluded recently, Florida is home to the largest population of people aged 65 and older, and this group ______ over 17 percent of the state’s population.
| A．takes up | B．holds up |
| C．makes up | D．keeps up |
People with simple names enjoy quicker career advancement because names which are hard to pronounce inspire negative _______ from superiors.
| A．consideration | B．consequences |
| C．expectations | D．reactions |
In South-East Asia, many farmers cannot afford _____ farm equipment such as tractors, so most of the work is done with human labour.
| A．considerate | B．conventional |
| C．confidential | D．correctional |
The first thing you must remember is that in order to succeed, it is almost compulsory that you ______ optimistic.
| A．be | B．are | C．must be | D．have been |
John can finish this task quickly ______ using better methods.
| A．on | B．in | C．by | D．at |