By the time Einstein was 14 years old, he ________ himself advanced mathematics.
| A．has taught | B．taught |
| C．had taught | D．was teaching |
Jane is______ researching into the life of wildlife and can’t spare time to care for his wife and children.
| A．absorbed to | B．occupied in | C．engaged to | D．concentrated to |
The Browns wrote to Mrs. Anmary to______ her warm reception during the visit to her sanatorium.
| A．acknowledge | B．consult | C．owe | D．evaluate |
My house is the only brick one on the street. It______ and you can’t miss it.
| A．sticks out | B．holds out | C．looks out | D．makes out |
—Don’t you know your computer has been inflected with viruses?
— Really？No wonder it hasn’t_______ as properly as before.
| A．managed | B．controlled | C．operated | D．appeared |
The three sisters decided to hold a family party to ______ their parents gold wedding.
| A．welcome | B．congratulate | C．memorize | D．celebrate |