—Look at these tracks．It __________ be a wolf．
—It needn't be．It be a fox．
| A．must ; could | B．may ; might |
| C．need ; must | D．could ; need |
（届安徽省马鞍山市高三第一次教学质量检测英语试卷）
Trust is needed in the whole society, which requires parents to obey their own rules and set a good example _______ children can trust them.
| A．soon after | B．as if | C．in case | D．so that |
（届江西省师大附中鹰潭一中宜春中学等重点中学高三联考英语试卷）
—What should we pay more attention to if we go camping in the mountains?
—Nothing special. Take a special pair of glasses _______ the wind there is strong and cold.
| A．even if | B．in case | C．providing that | D．so long as |
（届江苏省扬州中学高三4月阶段测试英语试卷）
________, Mr. Wells is scarcely in sympathy with the working class.
| A．Although he is a socialist | B．Even if he is a socialist |
| C．Being a socialist | D．Since he is a socialist |
（2014届山东省桓台第二中学高三4月检测考试英语试卷）
It suddenly occurred to me I hadn’t locked my door．
| A．which | B．where | C．that | D．whether |
（届陕西省西工大附中高三第六次模拟英语试卷）
—Mom, can I go out and play with my friends now?
—No, honey, you can’t _____ you haven’t recovered from the knee injury.
| A．until | B．before | C．as | D．unless |