1. Bubbles, flaws, and other irregularities diffuse the light that passes through stained glass, _________ the glass sparkle.

(A) which making
(B) and making
(C) making
(D) to making

2. Butane (A)is found (B)into both (C)oil and (d)natural gas.

3. (A)By 1920 the area of the United States (B)under cultivation had (C)more than doubled in just 50 years, and the national population (D)that surpassed 100 million.

4. Chromosomes are regarded today as the major carriers of genetic material, ________ of DNA and various types of protein.

(A) consisting
(B) as to consist
(C) consist
(D) which consisting

5. (A)Climate is the (B)primarily force (C)that distinguishes one biome, or major terrestrial region, from (D)another.