A. by
B. alone
C. for
D. from
第1题:
Most of the environmental problems are man-made.()
第2题:
A.When-Mouse-Up
B.When-Mouse-Move
C.When-Mouse-Down
D.When-Mouse-Click
E.When-Mouse-Leave
第3题:
Each life jacket light that has a non-replaceable power source must be replaced ______.
A.every 6 months after initial installation
B.every 12 months after initial installation
C.every 24 months after initial installation
D.on or before the expiration date of the power source
第4题:
I ()supper when I()someone knocking at the door.
A、made . . . Heard
B、made . . .was heard
C、was making . . . was hearing
D、was making . . . heard
第5题:
A. Every 5 minutes
B. Every 90 seconds
C. Every 60 seconds
D. Every 30 seconds
第6题:
下列哪种方式是用class选择器定义样式的
A.p{color: red}
B.p,h1{color: red}
C.. one{color: red}
D.#two{color: red}