In writing a composition, there must not be one sentence or even one word which is brought in ______.
| A．at random | B．at ease | C．on purpose | D．at times |
________ stopping polluting the earth ________ hope to live in a better environment.
| A．Only to; we can | B．Only to; can we |
| C．Only by; can we | D．Only by; we can |
His friends were ___________and encouraged him to publish his ideas, but Copernicus was cautious.
| A．technical | B．official |
| C．educated | D．enthusiastic |
Our school was ________ in 1925 and has a history of more than 80 years.
| A．set up | B．set off |
| C．set out | D．found |
Our class _______ 55 students at that time.
| A．consisted of | B．consists of |
| C．made up of | D．was consisting of |
Having never met with such a _____ problem, he felt _____ and didn’t know how to solve it.
| A．puzzling; puzzled | B．puzzled; puzzling |
| C．puzzling; puzzling | D．puzzled; puzzled |