The researchers found clear and convincing evidence _________ happiness is the key when it comes to better health and longer lives.
| A．where | B．whether | C．how | D．that |
Nowhere else along the coast _______ so far from land.
| A．is there such shallow water |
| B．is there so shallow water |
| C．there such shallow water is |
| D．there is such shallow water |
Knowing how to think clearly and how to speak correctly ________ one confidence.
| A．give | B．has given | C．have given | D．gives |
The visitors stood at the top of the mountain ________ east of the city, watching ______ burning sun rising.
| A．the; a | B．\; the | C．the; the | D．\; a |
_______ an important decision more on emotion（情感）than on reason, you will regret it sooner or later.
| A．Basing | B．Based | C．To base | D．Base |
When deeply lost in thought, _______ he often was, he would forget all about eating or sleeping.
| A．that | B．where | C．which | D．when |