1．Where unemployment and crime are high, it can be assumed(假定) that the latter is due to the former.
2．To my great surprise, he somehow managed to survive(幸存) the earthquake.
3．There wasn’t enough evidence(证据) to prove him guilty.Finally, he was set free.
4．Our headmaster gave a convincing(令人信服的) speech to persuade students to donate some money for the disaster area.
5．As an old teacher he has witnessed(见证) the great changes that have taken place in the school in the past thirty years.
6．You will be informed of the details at the appropriate(适当的) time.
7．It is said that human beings came into existence(存在) about millions of years ago.
8．The world we live in is full of unexplained(无法解释的) mysteries.
9．Since the 1990s, China has constructed(建造) many harbors for importing and exporting goods.
10．Kate is enthusiastic(热情的) about helping others and all of us like him.
