GRAMMAR

To choose the correct adverb, you have to translate it in Indonesia for ease.

1. Not all students have understood the topic. .... , Mr Anton has to end the lesson. He lets his students ask about the topic by texting him.

The first sentence and the second sentence is contrast. The first sentence tell us that some of his student don't understood those topic, but Mr. Anton has to end the class. Normally, if you want your student to understand, you have to teach them little longer than enough. The correct adverb is (However / But).

TL : Tidak semua murid paham sama materi. Tapi, Mr Anton harus mengakhiri kelas. Dia membolehkan siswa bertanya kepadanya dengan mengechat dia.

3. This adverb function is contrast. Because if you are nearly at beach and prefer to go there, the normal situation is you will not return and stay long in there but the beach is close. The correct adverb is (However / But )

TL : Kami sampai dekat dengan pantai. Tapi, kami harus pulang karena pantainya baru saja tutup.