Mark the letter A B, C, or D to indicate the sentence that is closest in meaning to each of the following questions.

1 thought she was ill because she was absent from class yesterday.

A. She might have been ill because she didn't go to school yesterday.

B. She should have been ill because she didn't go to school yesterday.

C. She must have been ill because she didn't go to school yesterday.

D. She could have been ill because she didn't go to school yesterday.

Quan sát hình 26.1 và hoàn thành các câu sau:

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

(A) Farther evidence is needed (B) before we can make any (C) judgments (D) about that person.

A. Farther 

B. before 

C. judgments 

D. about 

Cho các tập hợp các cá thể sinh vật sau:

(1)cá trắm cỏ trong ao;

(2) Cá rô phi đơn tính trong hồ

(3) Bèo trên mặt ao;

(4) Các cây ven hồ;

(5) Chuột trong vườn;

(6) Ốc bươu vàng ở ruộng lúa;

(7) Chim ở lũy tre làng.

Có bao nhiêu tập hợp sinh trên được coi là quần thể?

A. 2

B. 4

C. 3

D. 5