The word "astounding" is closest in meaning to which of following?

　　(A) surprising

　　(B) estimated

　　(C) encouraging

　　(D) sudden

　　199. It is lightweight, impermeable to liquids, readily cleaned and reused, durable yet fragile, and often very beautiful.

　　The word "durable" is closest in meaning to which of following?

　　(A) lasting

　　(B) delicate

　　(C) heavy

　　(D) plain

　　200. In effect, as molten glass cools, it progressively stiffens until rigid, but does so without setting up a network of interlocking crystals customarily associated with that process.

　　The word "customarily" is closest in meaning to which of following?

　　(A) naturally

　　(B) necessarily

　　(C) usually

　　(D) certainly