—How do you like TV shows Home with kids (家有儿女)?

—I think _______ you turn it on, you'll never be able to turn the TV off. [ ]

A. if

B. because

C. although

D. as

根据蜗杆的（）不同，蜗杆可分为圆柱蜗杆、环面蜗杆和锥蜗杆三种。

A.性能

B.用途

C.外形

D.尺寸