I am too tired. I _____ my homework all morning.
A have been doing B did C do D have done
Two-fifths of people have reported that they get a sunburn ______ to “deepen” a brown skin, despite the fact that getting a painful sunburn just once every two years can increase the possibility of skin cancer.
| A．on condition | B．at present |
| C．by accident | D．on purpose |
He was always too hard on himself, never spending one single penny more. But he acted ________ when he helped the poor old lady.
| A．cruelly | B．selflessly |
| C．actively | D．actually |
Researchers have invented _________ ears that look and act like the real ears, giving hope to patients missing all or part of their ears.
| A．technological | B．artificial |
| C．false | D．magical |
Ever since the food safety accident, the company has carried out _______ checks on milk products to make sure that they are of high quality..
| A．informal | B．universal |
| C．regular | D．equal |
The businessman is always encouraging his employees to ______ water-based sports, hoping to develop an amateur racing team in his own company.
| A．build up | B．set up | C．keep up | D．take up |