r答案：C分析：A，D可以先行排除；且判断不是（which are）m

r答案：C分析：A，D可以先行排除；且判断不是（which are）made of 的省略结构，否则之前的they 将毫无用处，排除B；the type of material （that） +宾语从句。还原： they are made of the type of material.

Kết quả (Anh) 1:

R answer: c: the A,D can be ruled out; and judge not (which are) made of elliptical structures, otherwise they would be of little use before, excluding B;the type of material (that) + the object clause. Restore: they are made of the type of material.

Kết quả (Anh) 2:

r Answer: C analysis: A, D can be excluded in advance; and the judgment is not (which are) made of the omission structure, otherwise they will be useless before, exclude B; the type of material (that) + object clause. Restore: they are made of the type of material.

Kết quả (Anh) 3:

R answer: C analysis: D, A can be first excluded; and the judgment is not (are made) of B omitted structure, otherwise the they will be useless, rule out the; type of material which (that) object clause. Reduction: are made of the they type of material.