填空题__________ (他们太埋头从事科学研究), not knowing what happened just outside their lab.

填空题Only the hardiest animals __________ (才能在严寒中生存).

填空题The author is ______ toward icebergs.

填空题How can we account for the formation of an iceberg

单项选择题A．He prefers staying at home because he doesn’t like to travel.B．He prefers taking a bus because the plane makes him nervous.C．He prefers taking a plane because the bus is too slow.D．He prefers travelling with the woman.

单项选择题A．Very cool weather.B．Very warm weather.C．Raining weather.D．Fair weather.

填空题The icebergs are dangerous because they are hidden __ and can turn over unexpectedly.

单项选择题A．1B．2C．3D．4

填空题executive

单项选择题A．It’s less expensive.B．It’s more comfortable.C．It’s faster.D．It’s more direct.