________ a child begins school, he enters a world of fierce competition where success and failure are clearly defined and measured.
| A．Before | B．Until | C．Whenever | D．The moment |
children believe they can succeed, they will never become totally independent．
| A．If | B．Though | C．Unless | D．When |
The climate conference was attended by 11,000 people, it the largest UN gathering ever held.
| A．making | B．to make | C．made | D．to be making |
Bob’s lectures covered a fairly wide range and I can’t sum up what he says in a few sentences.
| A．covered | B．conveyed | C．considered | D．commanded |
They don’t feel safe in our town at night because it so dangerous. There’s a robbery every week now.
| A．becomes | B．became | C．has become | D．had become |
We should bear in mind that social development and balance of nature should go in .
| A．company | B．sympathy | C．association | D．harmony |