1 . Gold was discovered near San Francisco in 1848, ________started a gold rush. （用适当的词填空）

2 . ____________ might be expected, each approach has its advantages and disadvantages. (用适当的词填空)

3 . Tickets for Universal Beijing Resort officially went on sale starting midnight on Sept 14, attracting lots of fans, ________ even led to a shutdown of the resort’s official app for a time. (用适当的词填空)