Their telephone number is 5675707. Have you ?
| A．written it down | B．written down it | C．written them down | D．written down them |
_________, when Marx was already ________, he began to learn Russian.
| A．In 1870s; in his fifties | B．In 1870s; in fifties |
| C．In the 1870s; in his fifties | D．In the1870s; in fifties |
He made a serious mistake, but he took action to change that _________ it got worse.
| A．until | B．when | C．because | D．before |
We should try our best to make ______ world that is safer, cleaner and healthier than ____ one we are living in now.
| A．the; / | B．a; / | C．the; the | D．a ;the |
—Hey, Tom. Let's go swimming.
—Just a moment. I______ a message.
| A．send | B．sent |
| C．am sending | D．have sent |
—What should we do to reduce food waste?
—In a restaurant only order as________ as we need and try to eat it up.
| A．most | B．more | C．much | D．many |