单选题 Electric eels use charges to detect prey and also_____them before they eat them.

单选题 I've never been to Beijing, but it's the place __.

单选题 The manager promised to keep me__ of how our business was going on.

单选题 The party had to be __ because the host went down with a bad case of flu.

单选题 The children went there to watch the iron tower__ .

单选题 —It's very windy and dusty in Beijing .—Well, more trees __ every year to stop the wind and sand.

单选题 Susan, will you please go and empty that drawer?— __?

单选题 ____difficulties we may come across, well help one another to overcome them.