LIFE ON OTHER PLANETS. TEST 1.

4. - BAI TAP TIENG ANH LOP 9 TRAC NGHIEM TU BAI 1 10
Lớp 9 BAI TAP TIENG ANH LOP 9 TRAC NGHIEM TU BAI 1 10

4. Scientist could not … about the egg- shaped object in some fields.

a. explaining b. to explain c. explain