________ the course very difficult，she decided to move to a lower level.(2013·北京，24)

A．Find? B．Finding

C．To find D．Found

Bears ________ fat stores throughout the summer and fall to have energy enough to last them through their winter sleep.????????????? ????????????? ????????????? ????????????? ????????????? ????????????? ????????????? ????????????? (2013·浙江，17)

A．pack up? B．build up

C．bring up? D．take up

There are some health problems that，when ________ in time，can become bigger ones later on.????????????? ????????????? ????????????? ????????????? ????????????? ????????????? ????????????? ????????????? ????????????? ????????????? (2013·浙江，19)

A．not treated? B．not being treated

C．not to be treated? D．not having been treated

Volunteering gives you a chance ________ lives，including your own.(2013·北京，21)

A．change? B．changing

C．changed? D．to change

Team leaders must ensure that all members ________ their natural desire to avoid the embarrassment associated with making mistakes.????????????? ????????????? ????????????? ????????????? ????????????? ????????????? (2013·江苏，29)

A．get over? B．look over

C．take over? D．come over