No matter how ______，scientists are eager to know more about it by exploring.
| A．an ocean may be deep | B．deep may an ocean be |
| C．deep an ocean may be | D．may an ocean be deep |
.
—Do you want to go to the cinema tonight?
—Sorry, I’m so tired. I ___________ an early night.
| A．have | B．am having | C．have had | D．had |
.
With age, the mineral content of human bones decreases, ________ them more fragile.
| A．make | B．to make | C．made | D．making |
.
Let's go a little faster, ______________ we'll never get there on time.
| A．yet | B．or | C．so | D．and |
.
—How long have you been here?
—Only about five minutes. Henry and Simon _____________ here with me.
| A．walk | B．have walked | C．walked | D．had walked |
.
—Was _________________ problem solved?
—We were trying to think of _________________ way out, but it was difficult to find one.
| A．a; a | B．a; the | C．the; a | D．the; the |