“不光铁会生锈，就连铜铝等金属也会生锈”一句是( )
A．并列复句
B．对立复句
C．递进复句
D．倚变复句
参考答案：C
________ astronauts cannot go to a baseball game or a movie in orbit , there are many familiar activities that they can still enjoy.
A．While
B．Since
C．Before
D．Unless
高强度螺栓靠本身的高强度来传力。
