25. Why does the author mention feldspar in line 10? (A) It is often used as a substitute for clay. (B) It is damaged by the oxides in clay. (C) Its presence indicates inferior clay. (D) It is a major component of clay.

29. The passage supports which of the following conclusions? (A) Clay deposits are only found deep in the Earth. (B) If clay contains too much iron it will melt when fired. (C) Only certain types of clay are appropriate for making china teacups. (D) If sufficient heat is applied, all clay will become nonporous.

25. Why does the author mention feldspar in line 10? (A) It is often used as a substitute for clay. (B) It is damaged by the oxides in clay. (C) Its presence indicates inferior clay. (D) It is a major component of clay.

其他試題

25. Why does the author mention feldspar in line 10?
(A) It is often used as a substitute for clay.
(B) It is damaged by the oxides in clay.
(C) Its presence indicates inferior clay.
(D) It is a major component of clay.